tirerack has a service where they will send the tires to one of their guys, the price is quoted to you when you order, if i remember correctly. if you are going for stock replacements, you can always try costco or BJ's. **** lot cheaper than the wholesalers. and their stock moves. huge turnover, and if it's a weird size, they will order for you. nice and fresh, right from the oven

 

i went to walmar and they said $5 per tire but it was late and the guy was lazy so he didn't charge me at all. most other placed are around $20 per tire

 

The average in my area seems to be about $8 a tire mounted and balanced and about $2 for a new stem. However, that is is you buy the tire from the place installing them.

From my past experience most places charge extra if you bring them the tires and dont buy them from the installer, as they wont be making any profit on the tires so they charge extra for the service.

It has been awhile since I checked though as I had a friend who did it for me for free and would sell me tires at cost, so I havent given much thought to if for several years.

Last time I bought tires was during a highway flat and didnt want to drive across town to his place so I went to the closest place on a nearly flat temporary(haha). Luckily, the place I went turned out to be where another friend who did tires had started working, so I got free installation (although the replacement of 2 tires till cost me almost $400, but he also fixed my bent rim for free...I guess it was for free as it isnt something they would normally do).