If you are going down the ebay route make sure the bowyer offers a reasonable guarantee of some kind. All wood is not equal even wood from the same tree!
A bamboo back will yeild a fast bow ( But i have found it a bit prone to splinters raising in my own experiments.) The glue lines in a laminate also store energy ( when bent they will want to return to their natural at rest position) so the more glue lines you have the more stable ( and safe) becomes. I presume this is why the number of laminates in ELBs in limited to 6 for some styles of shooting. ( They want the wood doing the work not a modern epoxy)
The above is my observation, not proven by extensive scientific testing and i am willing to be corrected by any more learned than I.
