My $.02 worth, deeply discounted...
The 172 is fine to train in. I started out in Cherokees, and stalls in them are such a non-event that doing one in a 172 was a real eye opener (you mean you actually have to USE the rudder pedals?) but still no big deal. As noted before, your instructor does not want to die so neither will you.
$175 per hour with an instructor probably isn't bad. The last time I looked, a rental 172 was close to 125 per hour here, and instructors were $40 per hour several years ago. I finished up my instruction in a flying club. That 172 cost me $86 per hour wet -- i think they're up to about 100 per hour now. If you can find a club close to you that has a suitable trainer of any sort (and allows primary training), you should seriously consider buying in.
If you don't already have a medical, you should get one. But... and this is my standard advice... DO NOT apply for an FAA medical of any sort, ever, unless and until you are 100.0% certain of passing. I cannot over-emphasize this. There are things most non-pilots would never imagine would get you denied, and if you are denied -- and can't get a "special issuance", usually at great personal expense and inconvenience -- you're permanently screwed and can't even fly as a Sport Pilot. Read and heed
@AggieMike88's advice.
You say the airport is 15 minutes from your house. If there's a way you can get more than 2 or 3 flights a month in, do it. Once a week is about the minimum I would recommend, twice a week would be better. Otherwise you'll spend half your time scraping off rust. You have to work with what you have, of course, but do what you can to get as much stick time as you can.
