I don't wish to shock anyone who sees the new value of $340 and panics, so I thought I'd explain what I have done.
I'm just going to keep updating the cumulative value needed and paid at the start of the months. So, last month was $195 (50 for setup), this and following months are $145. $195+145=340. Next month I'll up the total to $485, then $630 etc.
I think this is better or else what happens is the donor information from last month gets reset. It also helps to show you as a grand total at the end, how much you raised as a community effort to pay for the hosting costs, which I think is kinda cool.
Let me know if I overlooked any problems with this sort of setup. I do realize the thermometer is not going to look so bare as if it were reset back to 0->145 again, but willing to make that sacrifice for the other benefits.