Hi Kim,
I might be way off base on my answer but I guess you can always just try it. First of all you must be logged in, then at the top of the page is the heading My Trulia, run your cursor over that and another window pops up. In that window it will say listings, click on that and all of your listings should come up. Choose the listing that you want to change the price on and then click on Edit on that listing. I then believe another window will come up and you would want to click on listing information, when that opens you just change your price. Good Luck and I hope that I have no confused you to where you are pulling your hair out.......Hal