Hmm. Prosper is a deck that should go brrrr even when you don't always have the commander out. I play an upgraded precon and I found that adding every 2-mana artifact that produces mana as well as some extra things that exile more cards really makes the deck go off.
Should be pretty easy to upgrade for not that much. If you're interested, here's my list. It works very well. Could probably use with some additional protection for Prosper.
@troyunrau hmm. They look to me like wild rocks that have been fed enough to acclimatize them to people. Look how they're happy sitting on the porch near a high-traffic area waiting. That's probably where they get fed