Your best bet for a beginners Amiga setup is - and this all my humble opinion!....
1) Amiga 1200
2) 68030 accelerator with 32MB RAM
3) ~1Gig hard disk.
This'll give you most compatibility because you'll be able to run WHDload installed games (i.e. most of them) straight off your hard disk. Also the 68030 (preferably at 50MHz) is a good all-rounder, it's compatible but fast(ish!).
If you find you like what you see then you'll need a big box Amiga really such as an A4000, at which point you can start looking at graphics cards (essential for serious use of an Amiga really) and stuff.
The 1200 should set you back very little, ditto the HD. It's just the accelerator that'll cost.
Of course if you really want to get into it there's a ton of other stuff you can look at like PowerPC accelerators to run the latest AmigaOS 4.0 and things like that...
