You can still find a MSX2 modestly priced. I know the
MSX Resource Board has a forum where people can buy, trade and sell anything MSX related. You'd have to look outside eBay, and don't mind paying shipping from Europe or The Netherlands (The Netherlands is a hotbed of MSX hobbyism, don'tcha know). I bought my MSX2 (Sony HB-F1XDmk2) from Britain for the pound equivalent of $150, IIRC. MAKE SURE that the computer you are buying is a Japanese NTSC model and not a European PAL model, otherwise it will create more unneeded work and confusion, with the chance that you might not even be able to use it with an NTSC TV. Meanwhile, a 1chipMSX was only manufactured in select amounts, so any one you run across will probably command $$$. The last one I saw on eBay sat on a BIN for near $500. And then a Turbo-R model may even be more expensive than that -- the deluxe model of MSX computers. However, only a handful of games were specifically created for the Turbo-R, and the cost outweighs the benefits to me. Definitely try out some Turbo-R games in emulation before you plunk down cold hard cash for a machine.
As far as MSX1 recommendations go, any of Konami's flagship titles were developed for the MSX2, so they won't work in a MSX1, obviously. However, Antarctic Adventure, The Goonies, Green Beret, Hyper Olympics/Track & Field, Knightmare, Gradius I & II, Parodius, Salamander and Time Pilot are all good Konami developed MSX2 titles. Only problem is, most people familiar with the MSX system associate it with Konami games, thus, high prices. For MSX1 titles a bit more under the radar, try Toritorn (an action RPG), Ice World (Pengo clone), Xyzolog, Sweet Acorn and more. A good resource for looking up games with screenshots is
Generation MSX.