Rent or sell at what the market will bear. Pretty easy to figure out by looking at what others are asking. Ask more and your stuck; ask less and things move.......
TTT nailed it. You may have a formula intended to recover maintenance fees, ebay and PayPal fees, guest confirmations, etc., but you have to pay attention to the market. I use RedWeek.com (easy to find comparable listings), sometimes Craig's List (tedious finding comparable listings), and sometimes ebay for market analysis. Try to stay toward the lower end of the market if there are a lot of similar listings. Bump your price some if you are "one of a kind" or for high-demand, event weeks.
Since I have unlimited transactions, I don't care if a points-based reservation doesn't rent, and may price a bit higher because of that. I can cancel, recover the points, and reload with another reservation. It's totally different with fixed or floating weeks.
My ebay prices are about 10% higher than on other sites to cover the final value fee.