After a few years in the area, I think nobody publishes prices because in most marinas there's a huge discrepancy in what each renter is paying -- especially during first year contracts.
Sure, your first year might be $275 per month for a 35' slip, but then if you want to stay, it goes up to $300 the next year, maybe even $325 the next year. Then you have a huge mix of people paying different rates. Unfortunately, it's usually the ones who have been there the longest and actually pay on time that end up with the highest rates because the marinas think they can "afford it."
Marina Del Sol was the WORST about this. They claim to charge by the size of the boat, not the slip. I was paying almost $300 per month with a 27' boat while my friend had gotten the "boat show special" and was only being charged $175 per month for his 34' boat.
I'm at my second year at Watergate with a 35' slip paying $325 per month, but I'm sure if you called as a new customer wanting a 35' slip, they'd quote you a better rate.
However, I can say that Watergate puts a lot of work into maintaining the marina and dredging, so at least you see where your money