I know a certain shop that wanted to charge me $400 for a certain rear tyre, even after I've spent bucket loads there in the past.
Another unfamiliar shop offered me the same tyre at $235. I had him recheck his price, he triple checked his price too after I told him the oppositions price, turned out $235 was correct.
Neither shop was including fitting/balancing in the price.
Thats a pretty significant difference.

Hence, I no longer spend anything at the original shop.