What kind of 21 could you get today? Last April I drove 600 miles and bought a 97' 21 SC that had been garage kept and never beached. There was barely a scratch on the bottom of the hulls. The guy even had a brand new, still in the package, forward tramp.
I wish I could say it's still unblemished:::(((
As far as the weight, yeah it's heavy, but don't let that scare you. I don't know if it's really 600 pounds though. I have yet to figure out where the extra weight is compared to the 21SE. It's not in the cabin...
If you put your mind to it I'm sure you can over come that issue anyway. Someone suggested bringing a winch...may not need one if you disconnect the main sheet block and use it with a stake. You just need to get it up off the sand. PVC pipe, plastic deck wood strips or other would all work. I'm convinced you could move a mountain with PVC pipe.
You could also get these and stack them up on each side and make a "low boy" if you don't need to move it far.
http://cgi.ebay.com/4-Tough-Plastic-Whe ... dZViewItem