Fortunately, Bangkok remains very cheap by almost anyone's standards. If you want to splash down for a nice 3-star room then it'll be half the price of a similar room in Europe or the US, and if you are fine with something more basic then you can find a room for next to nothing, even in the fun Khaosan Road backpacker district. Street meals for around a dollar are always there too, so you'll be able to afford a bit more for a room anyway.
It would help to know your starting location, but I’ll assume it’s the US or Canada because you didn’t say. My first thought for this is Argentina, which of course is in mid spring in late October. Buenos Aires is a wonderful city with great food and culture. You could also visit Mendoza, which is the lovely wine region, and Bariloche, which is a mountain resort area with year-round activities and such. Then there is always the amazing Iguazu Falls on the border with Brazil and Paraguay. It’s by far the most amazing waterfalls and area I’ve seen. Things are pretty cheap in Argentina these days for outsiders because of their weak currency. It’s also got very good outdoor activities in many different areas that should have nice weather in late October. It’s easier if you know Spanish, but still doable if you don’t. I don’t speak Spanish and I enjoyed it so much I stayed for a month. Let me know if you have something else in mind and I can try again. -Roger
While December is quite busy in Lima, as a very popular summer beach destination for South Americans, it's also still very reasonably priced so it's worth considering if you are exploring the continent. The beaches aren't spectacular as they are in Brazil and elsewhere, but Lima is still a great summer city with great outdoor life this time of year.
Located off the coast of East Africa, the Seychelles—an archipelago consisting of 115 islands—is about as close to paradise as you can get. Crystal clear water, lush jungles, and powder-fine sand make it the ultimate early winter escape, particularly for romantic getaways. Book one of the 30 breathtaking pool villas at Six Senses Zil Pasyon, which is among the region's top luxury resorts. The hotel is situated on a private island that offers prime territory for snorkeling, sailing, kayaking, and hiking—plus, the spa has scenic pavilion-style treatment rooms that are worth the trip alone. Health conscious guests will be particularly impressed by the property's new "Eat with Six Senses" program, which is intended to make travelers leave vacation without the guilt that comes with overindulging. There are four tailor-made treatment plans that focus on sleep, detoxing, fitness, and more, depending on the issues you prefer to address.