Aha, just looked at Seeedstudio - it's not that simple - seems to be a $250 initial outlay for new designs doh
I've used Seeedstudio a few times. It is $50 for 10 boards...no other initial outlay. And you can get away with $30 for 5 boards if you give them permission to try and resell the other 5. Considering those options I really can't understand why one would be $30 for a single board from batchPCB. It's always good to have a spare anyway in case you screw up the assembly too bad and even if you have a few traces wrong you can patch it.
Originally they had a 1 board for $10 deal (and they actually sent me 3 which I thought was very nice of them) but I just dont' see how it's possible for them to make a profit on a deal like that, so I'm happy enough with the 10 for $50 offering.
fwiw, the boards fromt them are very high quality, comparable to the Arduino Diecimillas I've got except green instead of blue.