I've always heard these places try to rip you off and it's true, I experienced it first hand today with the GM Charlie.
I went in for a routine oil change and to have my tire pressure checked (low pressure light was on) for my company car. The GM informed me that there were 3 nails in my tired but that they would be able to seal the tires affected. My company pays for the repairs so I didn't bother to look at the receipt until I got home and noticed that it appeared that they charged me for two brand new tires which cost $247, so my total bill was 401.
I called and spoke to the GM who explained to me that he did not charge for two tires but just the repair and that's what it costs, 247 for a tire repair. I asked him more then once and he told me that was accurate.
I hung up and called another Jiffy Lube, who confirmed that I was in fact charged for 2 new tires and fees. I then called the GM back who again tried to lie about what he did and finally said let me check in the computer what I did and then finally admitted he charged me incorrectly "by accident" when it was clearly purposeful.
Very dishonest, do not go here!