Very very few installers actually stud the tires. They order tires from the local distributor which will stud as needed locally. Problem is those warehouses won’t sell to consumers. So you’re asking a shop to ask their supplier for a favor. And you’re asking them to transport a set of tires they didn’t make markup on two ways for nothing.

You saved money buying online because someone forfeited markup. The trade off is now you don’t get the service that markup pays for.