I'm offended. I can understand releasing a demo and asking for feedback to judge interest, but asking fans to pay for it and announcing the completion depends on sales?

If you don't think a game will sell well, develop it for digital distribution and minimize overhead costs. Heck, re-release the PSP port of 1 and 2 in the US if you want to profit from it, I'd pay for that. If I pay for a demo, I'd expect to get a discount or something on the final product.