If you know someone handy with a sewing machine and aren't too embarassed to ask them for help with this, a lot of that bondange stuff can be cheaper than bought. There is a certain "prestige" pricing done for these items since such a select group of people use them.
Fake leather can be bought at Wal Mart for $6 a yard and made into anything that will play well on camera. We used it mixed with dog chains in
Sheep's Clothing for the scene when the minister chains Gina to the bed. The sex shop chains and shackles looked a littler better but started at $40. Ours cost $2 for the chains (made 2 sets) and we used fake leather we had left over from something else.
Just something to ponder.