Sorry didn't snap any pictures when making my traps, but just picture the Ikea Billy bookshelf with a cotton bedsheet stapled over it and wheels
The billy bookshelfs I used is about 80 cm wide and 2 meter high, something like 40$ a piece. I calculated the price of wood to make the frame from scratch and it was 3 times that.
The rockwool terrain bats (Hmm, this is direct translation from Danish, I think the terrain bats is called something else in English) but the density is 90Kg/m3 which is great for bass traps.