Doesn't this mean that you could buy a pack of 10 for say 8 quid. Use 1 and then return the other 9 and get a refund of 9* individual price which is usually higher? 10 for 8 quid and 1 quid a piece would not be unusual and could result in them paying you a pound for using one piece of wood!
I'm not sure they would go for this some how :) Or do B&Q not sell the packs cheaper?
Darren