I agree you can not ask buyers to buy local.

My only beef with buyers are those that go to negative or dispute without contacting a seller to give them the opportunity to rectify any issues - I always send a Tax Invoice with a printed message -

Thank you for purchasing from XXXXX - in the unlikely event that you are not 100% satisfied with this item, please contact me immediately so I can rectify any problems as soon as possible.  Thank you blah blah,

In saying that, I offer warranty's as I am a registered distributor, so any faulty item costs me nothing other than the additional replacement postage so long as I can provide my supplier with photo proof of fault etc.