Three quotes, all wildly different -- what did YOU actually pay?

Does the $3,400 include the EVSE itself? Utility-recommended installer quotes very often bundle a $600-700 charger, a permit fee, a load calculation, and sometimes a 'site assessment' charge. Ask them to split out the hardware. That alone could explain a lot of the gap. My first install was $450 labor plus supplies, about $750 total, with an external conduit run. Price isn't what tells you a good electrician from a bad one. Ask whether he's pulling a permit, what wire gauge he's running, and what breaker brand he's using.

I paid $1300 to $1400 for a 50 amp outlet with about 50 feet of wire in conduit. That was labor and materials, no charger. Your run is a lot shorter than mine, so $1600 for 15 feet seems a bit high to me but not crazy. The guy quoting over text without seeing the panel is the one I would be careful with. He has no idea if you have room in the panel or what your service can handle. I am maxed out on my service now and could not add another big load if I wanted to. Someone should have looked before giving you a number.

$1,830 all-in for me, but that included the charger, and the charger was only $269 (Pion Flex). So call it around $1,560 for the install, in Southern Ontario. Your $1,600 guy is right in line with what I paid! I'd also check whether your utility's 'certified installer' has to be used to get a rebate. If the rebate's worth less than the ~$1,800 difference, I'm not sure what you'd be paying for.

The $3,400 one does include a charger, a ChargePoint I think. There's also a line for "load management consultation" at $350 and something called "commissioning" for $275. I have no idea what commissioning means for a wall box. The text guy did ask me to send a photo of the panel, for what it's worth. Not the same as coming out, I know.

Commissioning on a residential EVSE usually means they set the breaker size in the app and check that it charges. That's maybe 15 minutes of work. Load management consultation should be a load calculation, and on a normal house that's a worksheet. If your panel photo showed plenty of free capacity, it's reasonable that the $800 guy didn't bother. Still, ask him about the permit.

I've had a few installs done in Texas over the years and the cheapest one has been perfectly fine for going on 4 years. It was a solo guy too. What counts is whether he's licensed and pulls the permit, not whether he's a one-man shop.

Agree on the permit. If it gets inspected, the inspector is checking the work no matter which of the three you pick. That takes a lot of the risk out of going with the cheap one.

I paid $3600 for a 14-50, so I'm probably the outlier you don't want to hear from. In my case it was justified, though - the panel is in the basement at the opposite end of the house, and it turned into a lot of rewiring before they could get a run to the garage. The electrician walked through the whole thing with me before quoting, and I could see where the money was going. Your situation sounds like the opposite: panel on the other side of the garage wall, 15 feet. If it were me I'd be asking the $3400 outfit what makes up the gap once you take the charger out, because it isn't the wire. One other thing before you spend anything - have you tried just plugging into a regular outlet for a couple of weeks? Depending on your commute you may find L1 covers more than you'd expect, and then you're not in a rush to pick one.

I went with a small shop for mine after the bigger outfits all wanted to skip my existing sub panel and run a brand new line from the main. The one man shop looked at what I already had and worked with it... cost a lot less and passed inspection without any trouble. The solo guy isn't a red flag in itself. Just make sure he's licensed and pulling the permit, same as everyone said.

Ask the $800 guy what size breaker and wire he's planning. If he says 50A on 8 gauge, that would worry me more than the text quote does.