Some shop owner are friends, but business is business.
Will they honor the "shop guarantee" when their business close down?
Will they honor the "shop guarantee" when the item is not popular?
Basically with your savings consider that as a bet that you will not require any service within the warranty period, and if you need servicing within that warranty period then whatever extra you have to pay is your loss (of the bet).
Make sure the difference worth the bet.
Even with good brand, there will be cases of bad batch, etc. :sweat: Make your bet wisely.