O did the michies from Costco ...they also did Nitrogen fill at no cost which i always thought was a gimmick. That was 2 years ago and the pressure in them has not dropped since other than for temperature change. In my entire life I have never had a single tire that didn't need regular additional air.
Support your local brick store. If go cheap I don't expect to see you in the free air line at DT.
I gave up searching for free air years ago. Now I just carry a Ryobi tire inflator. I already have the batteries so the inflator is only $20 and I can fill them up anytime for free.
This has not been my experience. Online plus local shop installation is almost always cheaper, even if the local place has the same tires on sale!
Some online sellers will even list quotes from multiple local affiliate shops, or you can just call a local shop and ask their rate, and if you want addt'l support services then ask the rate for those too. Often it's just a different package price.
Did you ever ask for a price match? I had one local dealer charge $240 for a tire, found it online for $180 and they actually did match the price. Plus when you buy it online, they charged extra for mounting and balancing, but if you buy the tire there, then it was free mounting but they still charged for balancing so it was still cheaper than buying online. Of course if you don't ask for the price match, then it's more money.