Re: In need of tire help.
No problem.
From the photo (nice rig) you really have no easy option on changing sizes. Therefore, the easiest way to find an answer is to google "discount 175/80-13 tires Pennsylvania" and follow the links. You should have no problem locating an outlet. Just remember to compare apples to apples and not just price.
In my area of Central Florida I have found a supplier that it's cheaper to buy the entire wheel/tire set from him than a tire alone from somewhere else. I found him in the Yellow Pages, course this was before the internet, and then there is always "craigslist", or even "e-bay", just be careful of the shipping costs.
Luck