For going "cheap", level it and stabilize it with your stabilizer jacks. Then at each corner build up cinder blocks and lumber to where it just touches the frame. Then use shems and hammer them tight between the top of the cinder block - lumber support and the bottom of the trailer frame (much like they do with mobile homes when they set them up permanently).
This way, the main support is still on your stabilizer jacks, but the blocks are also bearing some of the weight, enough to keep the camper from shaking. I'd start with 4 sets of block, and if needed, a couple more near the axles, front and back of them.
Shorter Video. Click here. You Tube Video. Click here.The only problem I see with these videos though ... having worked a LOT with cinder blocks, the blocks need to be positioned up and down (holes on the top and bottom), not side to side. The strength is in the vertical position, not laying on their side. At the top, lay the board across the holes.
