I don't rent anymore. I purchased a plane when I could no longer afford to fly as much as I wanted and pay their rental fees. I also wanted to take some long trips where I'm gone for a week and most schools have a minimum of 4 hours per day around here if you're not flying locally.
Now, I have a cheap plane to operate in my Cessna 140. Even then, it's not dirt cheap. Hangar is approximately $3600/year, annual is $300, insurance is $600. Just based on those fixed costs and assuming nothing goes wrong, that's $4500/year. Divide that by 12 months, $375/month.
If you only fly for two hours per month, you'd be better off renting a $187/hour wet airplane. No maintenance, no hangar, etc.
If you're like me and fly 10 hours a month, that's only $37.50 per hour fixed costs, plus about $18/hour for fuel, so $55/hour which is pretty cheap. Even if you start an engine, maintenance fund of $10/hour, still cheaper than anything else I can rent and it's there whenever I want to go fly.
For grins I even calculated in the $28K purchase price even though I paid cash. $28K/5 years = $5600/year $5600/12 months = $466/month Fly 10 hours a month = $47/hour. So $47/hour + $37.50/hour + $18 Fuel + $10 Engine Fund = $112.50/hour for five years, then dropping to $65.50 per hour with a plane paid for in full. I also have a plane that's still worth at least $28K that I can sell anytime. In fact, I've had offers for more than that.
Yes, I'm married, and yes, I had to do a lot of justification to buy an airplane!