Dude, don't forget your power supply is for life, you may chop/change/add pedals at the drop of a hat whereas the PSU will stay throughout so I highly recommend getting something worthy. I have a diago powerstation and it's incredible, wether I am running just the one or my board with 7 pedals. No noise whatsoever and no worries about having enough/the right power.
Granted paying double what the pedal cost for the PSU may seem a bit daft, but remember with all your gear its an investment so it's worth taking the one off hit and getting the right thing for the job. Batteries are a hassle not to mention a never ending cost and a cheap PSU may not have the shelf live of the higher models or be as likely to handle all your pedals/any set up changes you may have. Cheap is not the way!