Please don't think I'm taking exception to your post - you raise a valid point. This is just how I see it.
I don't know how you are coming up with $80. The first controller - $36, and a $4.00 thermocouple comes to $40. Add the relay and your up to $55 plus some shipping. Toss in $10 for some additional nice to have hardware (mainly a receptacle to mount on your box) and you're at about the cost of the Lee pot. If you need to buy a box you can spend next to nothing or a lot depending on what you want. I figure that the reason to do this is you already have a Lee pot and are dissatisfied with the temperature control. That's a sunk cost and not pertinent to the money side anymore - it's already spent. You could sell the pot to help offset, but you won't get all your money back by a long shot.
For somebody wanting to fix what they already have and not afraid of a little electrical tinkering (my situation), this seems a very viable option to me. No, it doesn't quite hold as much as the RCBS pot, it's gonna drip some too. Assuming I blow the whole thing up, I can do this almost 3 times for what I'd spend on a single Pro-melt. Both ways melt lead, both ways will let you get good boolilts. You'll get something that works well (enough for me anyway) for a lot less than another $300 out of the wallet.
Again, not trying to step on toes, just presenting how I looked at it.