Went there in Dec. 2007 and ended up having to buy four new tires and front end alignment (car wasn't even two yet - 20,000 miles - good tread) - they talked me into all of it by saying that I had to do the front end alignment or the tire warranty wouldn't apply. Cost nearly $600 to have my (what I wanted - 2 front tires) replaced.
Went there with a car that needed a tire patched 3/30/2009 - I said I did NOT want 4 new tires for a car with 12,000 miles on it (Goodyear LS tires). Merchant's said could not be plugged - but didn't even look at the tire - then tried to sell me 4 new tires because buying 1 is bad for your car (different tread pattern). I said I wanted the tire patched - he said it shouldn't be done because a plug only lasts for a few miles. He told me I had to have a new tire - which would need to be special-ordered for $169 + extras. When I said I was going up the street to Goodyear, he told me they were a rip off and would charge me hundreds for the same tire.
Went to Goodyear right after - not only did they advise AGAINST wasting my money on a new tire, they pulled it in the bay, discovered a nail and plugged the tire, and did not charge me one cent for doing so. BTW - the tire Merchant's tried telling me was hundreds at Goodyear was actually $20 less than Merchant's charged for the exact same tire - and that's without all the extras Merchant's charges that Goodyear doesn't. I will NEVER go the Merchant's again - and will make sure I let everyone know about their dishonest service. Stay away from Merchant's - take your business to Goodyear!