Hi,
Welcome to A.org! Does your vanilla A1200 have a hard drive or is it completely vanilla?
A hard drive increases usability massively - grab a cheap old second-hand laptop drive and you'll be away! eBay is your friend - you may be able to also get a 68030 or better accelerator with some RAM on board.
I guess it's all down to how much you want to spend, plus what you intend doing with your Amiga.
It's all good fun, and before you know it, you'll have spent tonnes on it and ended up with loads more Amigas! Or is that just me?! :-)
- Ali