IL doesn't charge sales tax on precious metals like IN does, South Bend isn't THAT far from the border, the extra gas would pay off with any appreciable sized purchase. If you are looking to pick up 2-3 ounces here and there not so much.
Basically, you need to find a place that has decent turnover. A lot of the pawn shops originally barely okay prices and not much turnover. When silver went from $30 an ounce to $20 an ounce they had $25-27 an ounce tied into it and couldn't sell it at a loss. There is one up the road from me that has LOTS of silver, all at around $30 an ounce PLUS tax. I have a place near work in IL that I can usually get within $1.50 an ounce of spot for junk or .999, and no sales tax on it. There have been several decent deals on the equipment exchange precious metals section here, not frequently and if it is at or near spot it usually goes within minutes if it is just a couple hundred dollars worth. Prices range from just under spot to $3-4 an ounce over spot, you just need to be vigilant if you want to grab some.