It's about 60~70 dollars from Playasia for KH2:FM+ at the moment I believe. I didn't bother double checking the price there so it could be lower. All I remember was I bought mine for cheaper from Yesasia than on Playasia.
And your choice to get KH2:FM+. Like others have said, buying KH2:FM+ doesn't include how much extra you would have to spend to get it working on your NTSC or PAL PS2 (NTSC and PAL are the region codes for NA and Europe respectively. NTSC-J is from Japan). Assuming you don't have a PS2 from Japan, you need the use of Swap Magic or a Mod-chip to bypass the region lock. If you get Swap Magic, I resent the slide card as I hate how it whacks out the disc tray much more faster than under normal use, so get the Flip-top. Installation of the flip-top can be a pain though. Mod-chip? It's definitely a more expensive method including installation fees and buying the chip. I'd go against buying a mod-chip because of the raids recently a month ago but it's your choice really. Swap Magic is about 30 or less, no more. And a Mod-chip plus installation fees, assuming you get the DMS4, Crystal Chip or Matrix Infinity Green Dot, or perhaps even a modbo, is about 80~120 dollars depending on other factors.
As for playing KH2:FM+, it's a very import friendly game. The gameplay isn't too complex to understand so the controls and the system isn't incredibly hard to play but quite easy compared to importing like Growlanser. The only difficulty I see in playing KH2:FM+ is recognizing the kana characters fast enough to respond to the action on screen but practice makes perfect, right? Kanji is another story though. And since there's an option for English and Japanese like what FF12 Zodiac Job System has, it's your choice what audio you want to listen to. There's plenty of bonus treats, extra features and so forth, so it's totally up to you if buying the game will justify its cost. It is a remake after all. On a side note, one, if not, the biggest reasons why KH2:FM+ has less chances of coming here than an actual new JRPG game or so.
You could, however, if you have Gameshark 2 or Action Replay, to play KH2:FM+ without the need of Swap Magic or Mod-chip. Look up Cogswap. It's a longer process of swapping than using Swap Magic. But that's another story for another day that I wouldn't really recommend you trying to use since it's best to keep things simple.