Hi Rebecca!
where do you live?
All the major markets have garlic oil, all different price ranges.
How much are you thinking of making?
If you just want to infuse oil with garlic when cooking heat up some EVOO in a pan, dice or cut up a clove or two of garlic (or you can leave it whole), heat the oil on medium, pop the garlic in and keep an eye on it. If the garlic starts to turn brown it will be bitter.......just let it be in the hot olive oil for just a couple minutes or so.......that will infuse the oil with a garlic flavor, the stronger you want it use more garlic. I never have made it in large quantities, have only made it to use for whatever I am cooking at that moment. I imagine you could let the oil cool and put it in some type of container like an old washed out bottle of salad dressing or something. Hope this helps!