How much would it cost to change a flat tire without my own spare? I can get the car towed to the garage. About how long would that take?

For a tire patch, depending on the puncture, dollars, though, I've gone a few times and have patched up my tire free of charge.

Depends on what kind of car you have typically it's between 150 to $250

If the tire can be prepared, they will do it for free. If it cannot be repaired you will need to purchase a new tire ($90-150). I highly recommend using Discount Tire, they are extremely helpful and friendly.