Welcome to Geekhack!
HHKB or Pok3r would be excellent choices, both extremely popular keyboards.
Buying artisans, and even most keyboards and keycap sets, from OS you get used to our sucky exchange rate and increased shipping charges, it all comes with the territory. If funds are scarce, the thing to do is only buy the ones you really want, instead of every set you think you like the look of.
Most artisan keycaps are also generally available in (relatively small) batches, there are very, very few that are just "in stock" on a web site. It's been a while since ClickClack had any of his on EliteKeyboards, and even then it was a drawing (with, probably, thousands of entrants for, maybe, dozens of keycaps). No-one ever really knows the numbers, and that is part of the artisan scene.
Your best bet is to stalk the various artisan sub-fora, and checkout the respective rules when a new sale is announced.