I agree with Mac66 commits. I have donated once and would be willing to donate again in the future. It sounds like you are not wanting to have a huge amount of funds in your Paypal account. If you ever need extra funds for major upgrades don't feel bashful putting the word out to the members for help. I know there are a lot of people on this site that would be willing to help to have this site be as trouble free as possible.
I would have problem donating again if he ever needs it. If he keeps updating the site for the better, I am all in .