System was 35K. I also spent 15K on roof work, which included stripping the three layers there were on there, replacement of 35 sheets of rotted plywood, upgrading the attic venting, and new shingles. I knew the roof was a problem when I bought the house 10 years before. Pay back/break even was estimated to be 7 years by the installer. So far, 3 years 3 months later, this estimate appears to be mostly accurate:
$11,500 tax credits
$14,000 renewable energy credits (2K/yr x 7 years)
$ 8,400 in avoided electric bills (1,200/yr x 7 years)
I agree with a comment above, that it is much better to own the system, than it is to lease the system. Yes, it is costly up-front, but if you are planning to stay for the entire pay-back period and then some, it will be worth it. I've also heard horror stories that people with leased systems can have a hard time selling their houses, because the deed is encumbered by the solar lease, and some people don't want the lease, which is a better deal for the leasing company than it is for the home owner.
I'm the one accessing my roof, but it is only to clean the gutters. Hasn't been an issue for me yet. The system includes an external shut-off switch (required by code I believe) so the system can be rendered inactive from the outside of the house in case the FD needs to get on the roof to destroy it. I'm not worrying about shingle replacement, as the roof was re-constructed and re-roofed at the same time the panels went up. I'll be 80 when the shingles need to be replaced, if I'm still around.