I had my 28' boat shrink wrapped over the winter for the last 3 years. The cost was about $350 for everything - they build the frame, shrink wrap the boat, install vents, and a door.
I was very, very happy with shrink wrapping. The vents allow plenty of ventilation and the boat stayed very dry. The white plastic even allowed enough light through for a solar battery charger, left sitting on the deck, to keep the batteries charged.
My new boat (35') came with a winter cover. It's 3 large pieces of canvas type stuff. My boat is now out of the water
and in the yard. When I finish a few winterization tasks I'm going to try and cover the boat. The cover was made for mast up storage, and my mast is off the boat, so it will be interesting to see if I can make the cover work. If not. I will call the shrink wrap place right away.
In the yard I use, it's about 50 / 50 between shrink wrapped and tarps / over covers. I can tell you that at least 50% of the tarps, etc. don't make it through the winter. If you go down to the yard after a big storm, you will see lots of covers blowing around, doing a significant amount of damage. Last year I thought one guy was constructing a building around his boat! First good storm and it looked like the big bad wolf huffed and puffed and blew down his stick building. I have never seen a shrink wrapped boat have problems.
Anyway, it's up to you, if you cover it yourself, be careful in how you tie it down - don't go to the boat stands, don't let the cover chafe on the hull, don't let the frame fall down, etc.