I would have to ask about how much I’ll pay over the life of the agreement.
I see myself passing away in the house. My grandparents were the original owners of the house in 1948.
Be VERY careful of SunRun reps, my limited experience with them has them trying to mislead and not tell you the whole story. I had them approach me when I was cleaning out my parents old house, first she promised "free solar" that got her foot in the door, I was deathly curious what she offered so I set up an appointment so she could give her spiel, and the number of times she backtracked when I questioned the "true cost" was nothing short of fantastic, I don't know if she was just an ignorant sales person, or if that is the way they teach them to operate. Needless to say, none of her pitch had a fixed monthly cost, and when she sent their proposal, (looked similar to yours) I got a good laugh out of it. Anyways I ghosted her, until one day I accidentally answered my phone, and I basically told her I was not interested because that monthly cost is way too much, and ever the salesperson she was very agreeable for me too and said we should circle back once I start renting the house... just will not let me go. Unfortunately, I had to put her in my contacts list so I don't accidentally answer the phone again
That said, note that your monthly payments do not give you unlimited power, if you go above what you can produce (and use from the battery) you will pay for it. So you'll pay a minimum of $253.50 each month for the first year regardless of if you use that much power or not, if you use more you'll pay more... at PG&E rates, if you use less you'll pay... $253.50 they basically hold your power usage hostage. Get out of the hobby so there's no massive electric bill... you'll still be paying a steep amount per month, FYI most people are not in the hobby for 25 years too.
Just to run some numbers based on your original post. $253.50/month for year will be a minimum of $3042, year 2 with the 3.5% escalator it'll be 3148.47, again all of this assuming you do not use more than you make. At the end of year 25, $6945.89, and you'll have paid them $118,485.50 over that 25 year period. I'm not sure if they quoted you a price to buy the system, but for me the price to buy the system was roughly 1/3 the total amount that I would pay over that same time frame. Or to put it in investment terms, essentially giving me a 4.5% APR loan for the cost of the system so that I am allowed to lease their system. And I wouldn't be surprised if they would charge me to keep it at the end of the year.
tl;dr I would not enter into any PPA with any solar company, especially if they're talking about how they have a "special deal with PG&E", they are going to do everything they can to convince you that PG&E rates "historically outpace" what they're claim of rates are, which may be true but again if you give up the hobby you'll still be footing that big monthly bill and be contractually obligated to pay it or pay some pretty massive fees to get out of the contract. Basically say "no thank you" and run the other way, PPAs are not good business sense for most people.
If you really want to put a dent into your electric bill, get some estimates on a similar sized system from other solar providers, I'm guessing SunRun will do it for $40k based on the numbers I see, so that's a good place to start if you can scrap that kind of money together, or hell even get a loan for for it at a cheaper rate. And heck if you're handy, you could even partially do some of the work yourself and have it even cheaper, bulk pallets of panels can be had for 30-40 cents per watt these days.
