As Andy noted, the big question is, what are your responsibilities? Managing other mechanics, inventory, workflow, and customer retention demands much higher pay than simply being the "#1" mechanic in the shop.
The other big part of the situation: if you have already interviewed, and they've said they want to hire you, you are now negotiating your salary. Do not be afraid to do so, and do not sell yourself up the river for fear of them saying "no". A hard lesson to learn, and often one that many do not learn until much later.