You can't reuse shrink-wrap successfully more than the first season it is applied. You will get spots you can't properly tighten, which will trap snow and water/ice. Once it traps it, it will get very heavy, you will get tears and the like. Once you get tears, it will only spread, and ruin the shrink wrap, making it effectively useless. If you can't afford paying someone to wrap it, you can buy your own supplies and do it yourself, BUT, I guarantee it will not last the season.
Your options are one of the following 3. 1, blue tarp. Cheap, will last 1-2 seasons if you properly secure it, but will tear, it is hard to secure, and it quite frankly will look like garbage. 2, shrink wrap. Fairly cheap, looks excellent, when properly done won't tear, rip, fail, collect snow, or do any damage to your boat. 3, Custom Canvas Cover. VERY expensive. Bulky and "bothersome" to store and keep dry, clean, etc. Will last 10-12 seasons, and costs ABOUT 10x as much as Shrink Wrap.