I also think it's a perception of demand issue.
You would literally need to pay someone $100 to come to your house to change a light bulb.
The problem is that everyone understands that you need light. So, you pay.
I bet most Walmart racket players (91% of players) play with the same strings forever.
Maybe the other thing may be the pool of people who string.
Maybe a stringer at the tennis store is already there, just sitting there at the cash register doing nothing.
So, it costs the store nothing extra for labor of stringing, as it's subsidized by the already paid for labor.
So, they barely charge for it. Otherwise, I don't see how a store can be profitable charging $10 for a service
that takes 30-45 minutes when all is said and done. It takes several minutes just to ring out the customer.
It's not, but the $10 is all gravy, since the already getting paid worker is already just standing there doing nothing.
The other stringers are tennis nerds with day jobs who just string as a favor. If they relied on the income, they would not charge minimum wage. It's more like a favor.
So, it seems tennis stringing does not exist in a normal commercial labor marketplace, and that's why trades charge $150/hr and stringers get minimum wage.