I won't ship less than 100 baits... Just not worth it. Charge a fair price for the baits and have the buyer pay the $7.00 or so shipping... It's well worth their while to buy 300 or so at a time.
I have some old Bears hardener that is at least ten years old. It is really thick, like cold honey.
I find that I have to mix it in uncooked plastic until it's totally dissolved before I begin the heating process, or I wind up with hard lumps.