My guy at the hardware store said I could just wire two 110 outlets together to get 220 for my charger — is he messing with me?

He isn't making it up. People really do this, and they sell little boxes for it. It is still a terrible idea. The two breakers aren't tied together, so if one trips the other leg stays hot and you have a live pin on a plug you think is dead. Your 2019 garage outlets are almost certainly GFCI too, so there's a good chance it just trips constantly.

It does work in the sense that if you pick two outlets on opposite legs of the panel you will measure 240 VAC between the two hots. That is what he means by being careful which breakers you use. If both are on the same leg you get 0 volts. But those circuits are 15 or 20 amps each, probably 14 gauge in a lot of garages, and they are shared with whatever else is plugged in out there. An EVSE pulls a continuous load for hours, so you are limited to 80% of the breaker anyway. You would be taking all that risk to get maybe 12 amps at 240. A single 20 amp 2 pole circuit gets you the same thing legally and safely.

$800 sounds like an "EV" price. I had a licensed electrician put in a NEMA 6-20 for $300 -- charges our EV6 overnight no problem. Call around.

How far do you drive each day? I did my commute on the included Level 1 cord for months. It's slow, about 4 miles per hour, but it adds up overnight.

lol ok that's pretty unanimous. He did say something about the breakers being on "opposite sides" so I guess that's the leg thing. The 800 quote included a charger though, I think it was a ChargePoint or something, not sure if that changes anything

That changes it a lot, a wall unit alone can be $500-700 of that so $800 total with install is honestly not bad if the panel is close. Mine was $1300-1400 just for the outlet with 50 ft of wire and conduit and no charger. The other thing nobody talks about is after my install my service is maxed out and I cant add anything else big. On a 2019 house you are probably fine but dont let the side job guy near your panel either way.

Does your car not come with a mobile charger? Most do. If it can do 240V you don't need to buy a wall unit, just the outlet.