You're going to struggle to find official figures these days, but you could still get into Heroscape using a combination of:
1) Whatever official figures you can get your hands on;
2) Proxies of official figures; and,
3) Customs, whether they're from pseudo-official groups like
VC (C3V & SoV, a continuation of regular Heroscape),
C3G (comicbook superheroes - this is an amazing, vibrant group that's made far more figures than the official game, and which I'm actually proud to be a part of
)
HoSS (Star Wars - no personal familiarity with them, but I've heard nothing but good things), other people's personal customs (there's loads of great stuff around, which you can find
here, plus there's an
Index), and making your own figures and cards (trust me, creating your own stuff for this game is loads of fun!
)
Of course, you'll still need some terrain, and good luck getting all the terrain expansions. It's probably worth investing in a Master Set or two, especially if you're lucky enough to find one reasonably cheap, and if terrain starts getting stale then, again, customs and innovation are your friends!
There are loads of things out there that could make some great terrain, as long as you have the hexes to build a base map.
Also, there's
Online Heroscape now, and what figures and terrain you own is entirely irrelevant there.
Could be a good place to test things out before deciding whether to take the plunge and buy them.
Welcome - I hope you have a great time with this game!