I'm 43 and have been using Proscar, Minoxidil, and Nizoral for about 6 years now. I have about the same size bald spot (maybe just slightly smaller) that I had when I started.
Proscar is a DHT inhibitor. (DHT Inhibitors - Work to inhibit the binding of Testosterone and 5-Alpha Reductase, which in turn keeps DHT levels close to normal, which in turn helps keep hair growth and loss regulation at its normal healthy state.)
Minoxidil is a growth stimulator (Growth Stimulators - Work on a symptomatic level to artificially stimulate growth, without actually dealing with hair loss at the cause of the problem.)
Nizoral is an antiandrogen. (Antiandrogens - The goal of Antiandrogen treatments is to stop DHT from binding to the Androgen receptor. This is one of the steps in the chain of chemical reactions which ultimately leads to hair loss. Whereas DHT Inhibitors go to the first chemical interaction and stop it from occurring, Antiandrogens come in about 3/4 of the way down the process, and inhibit one of the last interactions before damage to the follicle occurs. Both types of treatments work in different parts of the process to stop the process from completing. )
Here's a great website to explain everything in detail:
http://www.hairlosstalk.com
As for propecia, I buy it online without a prescription at a cost of 47 Euros (1 Euro is approximately $1) for 28 5 mg Proscar tablets. I cut them in quarters with a pill cutter; taking one quarter/day. Here's the website that I order from:
http://www.qhi.co.uk/
If you find a place to get Proscar cheaper, let me know.