I know of quite a few companies that run day frames consisting of 4 2x6 boards bolted into a square. That's like, $20 worth of wood and bolts. My frame is 2 2x8 mahogany planks connected by 4 unistrut
cross-bars. I wouldn't trade my wood planks for ankle-breaker aluminium for any amount of money, and I don't think wood is ghetto for frames at all. I spent around $200 including all oar towers, thole-pins, and hardware, and probably $120 of that was the expensive wood. I've even been surprised at the longevity of the pieces of 3/8 plywood that comprise decking on 2 auxiliary frames I run.