$40-50 for a marathon is reasonable. $30-40 for a half is getting high. $25-35 for a 10k is out of the question.
I found the topo map to be very confusing – probably because I’ve never read maps like that. I’d rather just have a profile view.
DON’T duplicate awards, meaning if you give awards to the top-3 finishers, those 3 people should be excluded from age group awards.
Speaking of age groups, I’d go with < 19, 20-29, etc. 13-18 and 19-29 are not "standard". In the 10k and half I'd probably even go something like < 14, 15-19, etc. I hate the "everyone has to be a winner" mentality I see in a lot of places, but it's not really "fair" for a 13 year old to be lumped with an 18 or 19 year old. So if you're going to break up the < 20 runners, make it a little more even. If not, you might as well just go with < 19.
While marathonguide.com has the results in an easy-to-read format, your site is a little confusing. You have marathon, half, and 10k all on the same link. You don’t list finish times (kind of important) and you don’t list overall place. Some of the stuff you do list is not as important, like race # and exact age.
With ~30 finishers, is it cost effective to have medals made?
Finally, Whistle Stop sent out a electronic survey after the race. If you really want to get useful feedback, what better way than to ask the people that ran the race?