Good idea Grant. :)
I voted for 400-700.... I currently roast 700gm batches (green weight) and find myself roasting once a week or fortnight and doing 2-3 batches in a row.
About a kilo a week seems to be my consumption... well not just me! Wife, vistors, work-mates etc all love the home roasted specialty coffees! (they love em more so if someone else roasts them!!!!) ;)
I could live with a 300gm roaster (would be about 250gm roasted) if it was quiet, small and easy to use/clean.
It would need to work like a toaster... insert beans, press GO and come back to find perfectly roasted, cool coffee beans.
...oh yeah, it would have to cost about $50 :o