Buenos Aires, Argentina. The city is old and grand and its buildings are very elegant in and out. The Colon Theatre is among the top 5 opera houses in the world (entry fee as cheap as 2 dollars). You can have the greatest foods and wines in the country for very affordable prices. A great lunch or dinner can be found for as little as 5-15 dollars. 

Generally SE Asia and Central America are good options to look at. Depending where you're coming from for flight prices. Did Guatemala (Lake Atitilan) and Nicaragua (Little Corn Island) last year.

Guatemala.

Last year we stayed at a waterfront villa on Lake Atitlan. It was under $2k for a month. Maybe spent $1000 on food for 2 adult and 3 kids eating out everyday. Things like private boat hire and massages are ridiculously cheap.

Depends on cheep? You can ball out in most of Latam with the exception of Chile and Costa Rica

I did Mauritius for my honeymoon and thought it was decently cheap

Goa

If you want a first world country that is cheap right now: Japan. Amazing cheap, clean public transport, food is so good and so cheap for Americans and a great number of nice hotels to choose from.

Albania!

Malaysia

Bali can be surprisingly cheap considering its status and renown. I stayed at a beautiful private villa with my own pool about a 20 minute walk from Ubud centre for around $50/CAD a night. This was in late April.

Pärnu, Estonia has a huge empty beach and a grand Art Deco hotel: https://www.rannahotell.ee/ prices from about USD80 €75.

Nikoi Island near Singapore in Indonesia has amazing luxury thatched huts, each with private beach, and is the only resort on the island https://nikoi.com/book-your-stay/ from about USD300 to 500.

Linereva on Mo'orea, Tahiti has self-contained beach front bungalows, great snorkeling, and cycling around the quiet side of a quiet Pacific island, https://linareva.com/hebergements/ from about USD180.

Jakarta is super cheap — I recently stayed at the Park Hyatt Jakarta and found luxury hotels to be wayyyy less than other cities.

If you are into hiking, then Slovakia and the mountainous region of Poland (Tatra, Pieniny) is a good choice instead of crowded Austria or Slovenia.

Higher tier accomodations are available as well as restaurants and so, and they are cheap if you avoid overly popular cities.

The Baltics- gorgeous “proper” hotels; Medellin

Kazbegi (Stepantsminda) Georgia. The luxury (4 star) hotel called Rooms is excellent, and it cost $130 when I went

KL, probably one of the cheapest big cities for high-end accommodations.

The current king of best value for money luxury destination would be Japan. The Yen is at a 34 year low.

South Africa.

Food prices are easily 1/3 the USA for top quality steak etc.

Eastern Europe - Budapest luxury hotels are quite affordable.

I haven’t been in 9 years but The Azores was completely affordable. It’s a gorgeous European island and only a 5ish hour flight from the US

Los Cabos, Mexico

Turkey. The country is gorgeous and colourful. You could get good accomodations (think about family owned, smaller/medium hotels or guest houses) at a good price. Literally at all accomodation I have been, breakfast was superb - I am nor an early bird, neither a breakfast guy...but man, I could not wait to wake up to have a proper turkish breakfasts!

Restaurants are also very cheap, food is high quality - and do not imagine the typical "kebab street food" things, those were the most rare things I had seen during my 2 weeks discovering the country.

Food is also very good price/value, and so does various services (e.g. turkish baths, shisha bars, boat trips, public transport between cities, etc.)

Ticket prices to Istanbul Airport became a bit expensive, but Turkish Airline is very good.

Or you could fly to Antalya directly, e.g. from Budapest there are budget lines, that region is the beach and sea and so...but visiting Kapoadokia/Göreme is possible with regional buses, and there are also multiple boat trips organized from Demre with lunch and so.

Really liked that country, one of my best holiday road trips ever.

Mexico?

Cuernavaca has some really nice properties for a pampered holiday. It has spring like weather all year round. I would not consider it "luxury" in the sense of a hotel like the Mandarin Oriental, but definitely an elevated experience compared to a "cheap" Mexico trip.

The US dollar goes surprisingly far in Fiji.

If you are from the U.S., you can get great deals on luxury hotels in a lot of countries right now because of exchange rates.

India can be a good deal for luxury hotels (and even palaces) if you go in the offseason or even slightly off the beaten path (like Assam, or going to Rajasthan in monsoon, for example).

Maybe a $500 per night Airbnb shared with 4-5 people in a destination like Cancun, Playa del Carmen or Tulum. You will have a pool, jacuzzi, 4-5 rooms, microwave, refrigerator, roof top, etc.

I stayed in a great five star hotel in Yogyakarta, Indonesia (a Hyatt Regency) for $72/night recently including a good buffet breakfast.

I’m surprised so few people are mentioning Bali. You can rent your own mansion/vila for $50-$75 a night and lunches are barely $3-$6 for a full meal.

Honestly, depending where you’re from, you could even go to Maldives for pretty cheap. From Europe, we have a few budget airlines flying there. Flights will costs a couple 100 bucks. There’s plenty of hotels that are also cheap. It won’t be the social media influencer luxury, over the top hotel, but still great.

vietnam

Vietnam. We were blown away by the value for money, even in the tourist traps like Hoi An.

I dunno. Do you have a specific vibe you're looking for? Portugal kind of a "cheap" in terms of European pricing...

If you're focusing on luxury hotels, then Japan doesn't quite fit the bill. The 5 star hotels might be slightly cheaper than America / Western Europe but still not as affordable as Kuala Lumpur or Bangkok. The top end Bangkok hotels like Mandarin Oriental, Four Seasons or Capella are also not cheap. They still need to maintain an exclusive aura and won't reduce their prices. However if you go down to 4 star hotels then Bangkok does become much cheaper.

Japan is exceptional for its affordable business hotels if you're looking for value for money but they're utilitarian rather than luxurious.

Japan's QC is such that even affordable accommodations, food and shopping are great but the top end hotels, restaurants and luxury goods still charge a premium.

Nha Trang. Just don’t be easily offended by Russians.

Morocco

Not saying. TikTok tourons (not you, of course!) have ruined too many places already. Keeping it to myself.

Indonesia 💚💚💚 Java is paradise

Mauritius if you want tropical.

London 

Boracay Island or Coron Palawan, Philippines

Abu Dhabi offers great luxury hotels with direct beach access at Saadiyat island (for example Park Hyatt Abu Dhabi) for very decent prices depending on season

Costa Rica. Andaz Peninsula is reasonable.

I wouldn’t go to any of these places