Isolation disc for speaker spikes on wood floors.

Just did a little search, and it goes from pretty reasonable to quite expensive. Isoclean prices them as sets of 4, while others like Black Diamond and Symposium each. The BDR's are $30 each, but I need 8, so these things aren't cheap. The Isoclean's are $160/4, so they would run over $300. My sources are Music Direct, and Acoustic Sounds so far.