In general we plan to stop at a marina about every 7 to 10 days while we are here in the US. We much prefer to anchor out or stay on a mooring as they are quieter and far less expensive, especially anchoring which is free.
While in the marina we'll restock with perishable goods, fill the water tanks, empty the holding tank, take a long hot shower, do laundry and hopefully enjoy good wifi. Depending on our arrival time we'll stay one or two nights.
Marinas can be budget busters. In the Metro NY area rates run from $3 to over $4 a foot per night. Second Star is 36 feet long so the fees add up quick. Moorings generally run from $30 to $50 a night, a more affordable option but still expensive.