I plan to back this, but the 72 pin connectors in the NES are easily salvageable and fixable assuming the pins aren't corroded or broken.
I take a paperclip and use it realign all the pins, and I use an old invalid credit card wrapped with a coffee filter soaked in rubbing alcohol to clean the pins.
Never had to replace one yet (I have 3 NES and 1 Toploader).