Safe place for private sales/swaps wirh AC outlet?

That's probably asking a lot, but some cities have public places intended for Craigslist-like transactions, and some of those have power outlets so you can test out something before buying.

Just wondering because I'm cleaning out my garage and have a bunch of stuff listed, and it's awkward to have random people showing up at my place. I have an inverter to power small stuff, but it won't come close to powering the turbo entabulator or bivalve chlorotron.