I'd love to do something like this. If you keep it simple like the Studio 1 or 2 PI (bookshelf), it shouldn't be that difficult or expensive as long as you don't care how they look.I bet you can built two pairs of MDF and two pairs of birch ply for just over $150 in material. In one day too if you have enough clamps.
What's stopping me isn't so much cost or time, but explaining to my wife why there are now four more pairs of speaker cabinets in the house. I already have 3 pairs of unused DIY cabinets sitting (or taking up space) in my basement.
Gar.