We are planning some kind of graduation party for my son in June. He doesn't want a big party, but you know how these things tend to snowball. Anyway, there will be more people in my yard then fit in my house - so I need contingency plans in case it rains. My sister used to have a large tarp that we borrowed, it had sides that you could put down if it got windy or rained - but that has bitten the dust. I'm not sure where to look to find an affordable tent/tarp like she had to buy - or should we just rent one? Has anyone rented and how much do they run?