You can modify the motherboard somehow, and replace the Fat Agnus (Fat Lady) with a Fatter Agnus, and thus convert the 512k of FAST RAM to an additional 512k of CHIP RAM. (Ask rkauer, I got this info from him :-D)
Then, you can get a MegAChip (or one of the other 2M CHIP RAM expanders) and have the full 2M of CHIP RAM. Granted, these can be more expensive than they are expansive.
EDIT - You cannot use the 2M Agnus without adding more RAM, via one of the 2M CHIP RAM expanders.
You can put the 1M Agnus in and you will still have 512k CHIP and 512k FAST, unless you modify the motherboard. I have done this to several A500s but the A2000 is different. I'm not quite sure what you have to modify.
