Sandusky has tons of Hotels in all different price ranges. Try a search on the Sandusky and there visitors bureau. We used to stay at the Econolodge when we were up there early in the year working on my old cruiser. It wasn't too bad for a cheap place. The Green tree inn is at the end of the causeway and may be a bit cheaper than the big chains. Sorry I don't have numbers for you but I'm sure you can find them with the search of Sandusky.
If you want to stay out of the area I would suggest Elyria or Lorain they are only 30 Min to the East.
If you want to stay for free you can spend the night on my Hydrohoist Slip # 823 at Cedar Point Marina Boat won't be in the water till June
If you have a hard time finding info email me and I'll make some calls