With an additional donation from blogfriend Alan, I'm actually above the $450 mark now. And deals on potential replacement systems seem to be more plentiful.
I've started the PayPal verification process. It's another case of hurry-up-and-wait. In this case, I decided to link a checking account. When you do this, they make two very small (< $1) deposits to the account you specify (hey, money for nothing, yes?), and as soon as they show up, you go back to PayPal and input the amounts so they know that it was yours.
Catch: you have to wait 3-5 days for the deposits to show up.
I think I may have a few more donations coming in. I hope I hope I hope. People's generosity is a sustaining force these days. During these hard times, it's especially encouraging.