Hi mate!
The A1200 is definitly a very good choice. You should be able to get a really nice "entry" set for about 300€ (~400$ i'd assume), with an A1200 in near-mint condition, a 68030 acceleration board and 4MB extra RAM, as well as some (original) AGA/ECS games and a PCMCIA kit for file transfer. Oh, and a CF-Card + Adapter for the IDE port; 4GB is plenty, tho i've been fooling around with 16GB disks lately ...
If you want to hook the whole thing up to a modern TFT/LED/Monitor instead of a TV or an original Amiga capable monitor, a Indivision Mk2 appears to be *the* thing - i yet have to acquire one of those, tho.
Right now there also is a chance to buy a original packed A1200 Magic Pack (still sealed) as Petro somehow akquired a LOT of those from some forgotten storage or something like this. He takes 150 Euros + 19% VAT + Shipping per piece, which i consider a very fair price for original sealed A1200 magic packs O.o
So, i'd say get started with a magic pack and buy the other stuff and put it in (accelerator, CF-Disk, PCMCIA Disk Transfer kit); Or get one of the complete packs from ebay that usually come with everthing.
When you want to expand, you can always buy a better acceleration card that supports a lot more RAM, an indivision MK2, an IDEFix and a CDROM Drive, ...
Good luck,
- G
@Itix:
Working A1200's in good condition with the necessary stuff like mouse, PSU, ... for under 50 €/$? Guess there is a huge price difference between where you live and middle europe

Granted, you can have a lucky strike on some flea-market sites (or real flea markets) because some people dont know what stuff is worth, tho.