@Zabasaz:
Heroscape has some cool minis, and there's actually an official D&D expansion for it, with repurposed D&D minis. The problem for D&D (especially 4E), is that Heroscape bases are about an inch and a quarter across, so they don't fit into standard 4E grid maps.
The new Pathfinder minis are, imho, well-done but a bit pricey - especially since you get a single random blind-draw mini in a pack (ok, two if they're Small - but that's also randomly determined).
As to demos of games, as I posted above, I tried that in cooperation with CFG for a couple of months last year. I ran DC Adventures (M&M 3rd Edition) for about a month and a half, and Savage Worlds for a month. The turnout was tiny, usually a small subset of my regular Encounters players. I did turn one of my players onto Savage Worlds, which he now also runs a couple of campaigns with, so it wasn't a complete waste, but not very successful. Again, I'd really encourage you to try it, but you may want to try to think of how to promote it better than I did.
And yes, I'm currently running a Star Wars campaign using Savage Worlds (with homebrew elements) on Tuesdays. The minis aren't actually mine - they belong to one of the players. But, yes, my collection of RPG materials is significant (to say the least).
If you'd like to chat about how to get some sort of RPG demo program up and running, I'm definitely available.