First of all, you don't need to donate. Also, note that the money you donate isn't meant to cover the hosting costs (which are very low), but to reward my work. All in all, I probably worked for 30 hours on the new WMDB.
I host the WMDB on a server I have anyway, so there are no hosting costs. The only costs are the domain, which is 15 EUR per year.
All donated money will probably go into buying Tool recordings. I have none of them yet.