I'm planning to CD too. I do make my own, so that saves me alot of money - I can use the really good materials and not break the bank, thanks to wonderful fabric co-ops.
Of the commercial ones, I've used Fuzzi Bunz (good but just don't fit my son's weird body shape well), tried on a Happy Heiny (*really* didn't fit my son's weird body shape), Luke's Drawers (fit), LHC (fit)... and I've used Bummis SWW covers and Prorap covers when he was an itty bitty thing, combined with prefolds. I still have the prefolds, but hope to have enough fitteds that I won't have to use them! Prefolds are super cheap and versatile, but I go through love and hate cycles with them.
I haven't tried any of the other popular WAHM diapers, since I learned to make my own and couldn't see spending the money on something that may or may not fit my son, when my own pattern fits him perfectly. But he's just a weird shape - big waist and itty bitty thighs.
You can get some really great diapers used - check out the TP and Diaper Swappers. I'd purchase through those before I'd go through Ebay personally (good places to sell too, since you don't have to pay fees!).
Check Diaper Pin for reviews of various brands. There are some cheap brands that are cheap for a reason (ie, poor quality). So don't let cost of a diaper completely drive your decision. I won't pay $40 for a diaper, personally, but a $10 AIO new just might be too good to be true.