10k down, 1/2 marathon coming up!

I have now completed my first organized run as an adult. It was fun! A lot of fun and I am worried that I may have to sign up for more. The nice thing about running is that you are working consistently. Even if it is raining, I do not get cold while running. I love that! Plus the friend who talked me into this crazy thing in the first place, runs at the same pace I do. It’s really a pretty sweet set up.
Now for the dilemma; I need new running shoes. I went to a running store and had them take a quick look at my shoes and they told me about how many miles I had left on them and they also told me a bit about my running style. I figured I would just use up the miles left on my current shoes (which they said were not a bad fit for me) and then I would go back to the store, pay them for the service of fitting some shoes to me, and then go buy them with my discount at REI.
Then I called them to ask how much they would charge for a fitting. Apparently there is no possible way to charge for just a fitting. I assumed that the running store would be like my dad’s bike shop in this respect. Offering complementary fittings for those who buy from the store or charging a fee for those who wish to buy elsewhere for some reason. This is not the case in the running industry, not in Portland anyway.
So now I am really torn between two things I love dearly: saving money and supporting local, small businesses who are great at what they do. This is all complicated by a few things.
1. I have already gotten some good advice from them for which they have in no way been compensated.
2. I am extremely broke right now and that is not going to change for some time to come, like maybe a year or more.
3. My body is full of weirdness because of my back and having broken my leg a few years ago so I really do need professional advice.
4. The guy at the store told me that since I was honest about my intent to buy elsewhere, he would run through a fitting with me for free if I came in on a weekday when the store is empty.
For the record, that fourth item does nothing to alleviate my conscience. I know what it is like to be in an independent shop. The guy is being nice because he really loves running and he wants me and everyone else to love running too. He is speaking as a runner not as a business man. I don’t feel comfortable taking advantage of that. I also don’t feel comfortable spending over 100 bucks on shoes. What is a girl to do? Seriously, I could use some advice (or some money)here because those old shoes are on their last legs.