Here's one I built from a piece of scrap lying around my old man's shop. I bought the aluminum edging and the handles. The velcro I already had and the black paint and all the squaredrive screws I bogarted as well. I probably spent around $15 tops, if you don't count the crapload of money I dropped on a bigass roll of industrial velcro.
I just cut the ply on the table saw, then ran the board through on its edges to take about 1/16 off the thickness so I could get the aluminum over the velcro. It took longer to cut the miters in the aluminum than anything else. All said and done, it probably took about 3 hours to make. If you already had some plywood lying around and some auto carpet or a 2" roll of industrial velcro, it'd be cheap. If you had to buy a whole sheet of ply, might as well make a couple and sell them on the side.
Here's mine. It's not the nicest looking board, but it works ok. There is power hiding underneath the upper level. The only problem is my pedals are too big to fit on there. I'm gonna make a new one to fit my latest pedals soon.
Here's mine. About the size of a pedal train pro. The case is a flight case from rondomusic.com. It was about $90 after shipping, and the pedal board is made of 1x2's screwed together, spray painted black, and velcro. I used an angled piece of plywood for a while and drilled holes for the cables, but when I started moving things I had to make too many new holes. This allows me to clean up my cables, have a strong and removable board, and fits custom to my case.
I got the case on ebay from Seismic Audio, but it looks like they aren't selling them anymore. The board is about the size of a Pedaltrain 2 and is made from 1/2 inch plywood that I put a black plastic veneer on. I have a pedal power 2 under the riser. I probably have $80 into it.