If you think you’ll donate enough for a Friend E-Peen at some point, why not buy it right away? It’s more efficient anyway.

I don’t know who posted it, but a while back someone said “Check the packages, see what you want/need: don’t get that one, get the next. You won’t regret it.” Turned out true for me.

Edit: I updated the wiki with the exact requirements for the Friend peens which were lacking.