I sometimes think it's worth a chance seeing just 
HOW stuck they are.  Two of my prize possessions 
came to me "stuck to sketch."  One wasn't, or at 
least no more than any cel that gets shipped in 
the same envelope as the sketch, and so 5 minutes 
after I'd opened the package I had a perfectly 
good cel and unstuck sketch.  Another was stuck 
all right, but just in one little spot where a 
little wetting let me get the two away with no 
damage to the cel and just a little to the sketch.

So for a bargain I'm willing to take a little 
risk once in a while.