We used a Haier "portable" washer when we lived in a small apartment and used cloth diapers for our first kid. It was around $200, purchased from now-defunct retailer Circuit City, and well worth it. It even handled DH's messy farm clothes. Limited capacity, so laundry was done quite often, and really big stuff (like comforters or other bed-things) still had to go to the laundromat. But we don't wash that stuff often, anyway... But really, a family of 3 including a baby using cloth diapers? It was a little workhorse.
We used it solidly for over a year, and then moved to a place with a "real" washer. On a couple of occasions, the large washer has been out of service, and the little guy has been brought back out to fill in. Still works, last time we pulled it out.