There are as many opinions as there are uros.
I'll suggest that you get a copy of Dr. John P. Mulhall's "Saving Your Sex Life". He is a well-respected doctor in the area of urology at MSKCC. The book covers a lot of rehab options. He also has some video presentations online.
My insurance will only pay 8 pills per month, regardless of strength or drug name. Since my uro wants me to take 5mg of Cialis per day, I have no option but to buy the 20mg pills and cut them into (more or less) quarters. Since they are hard to cut in any sort of equal parts (due to the shape), and it stays in your system, I just arrange the sizes of the cut pieces to resemble some sort of balance.
Yes, they are expensive, with 20mg Cialis coming in at $20 or more per pill. I blow out my ultra-high deductible fairly quickly.
Whenever you see a doctor (uro, gp, doesn't matter) beg politely for samples.
Cialis does a "first month free", but you have to play the game so as not to aggravate the insurance company. Get a prescription for the 5mg (30 pills), and go on the Cialis site to get a coupon for the free month. Go get that filled (you can get one free fill per year). At the same time, get a prescription for your 5 20mg pills, and fill that the next month on the insurance. No freebie there, but you get a month free overall, then switch to the highest dose and cut them up.
Also, if you can get samples of any of the others (Levitra, Staxyn, Viagra), ask your doc about using them. I use what I get just to see if changing pills improves things.