I currently run a Printrbot Plus (v2.1) and it has a heated bed. We started out by printing onto heated Kapton Tape at 70 degrees Celsius and the print would slide off halfway through the job. Tried to diagnose a bunch of problems, including drafts, adhesion, etc... The answer was putting blue painters tape on the heated platform. FYI I'm using that to print parts for the gMax I'm building right now.
The reason people heat the platform, officially, is that ABS must be printed on a warm surface. This is one of those givens that not many people question. The really good, expensive, printers will heat the entire build chamber, which may be something you want to do if you print with ABS using the disk heaters as Gordon suggested. I print with PLA, which does not require a heated surface, but we use one anyways. It is a little annoying, waiting for the bed to heat up and cool down between prints, so there should be a certain satisfaction to: print done, pull off the bed, and get the next print started within moments. Looking forward to that myself.
Going back to your question: it's not a waste if there's a reason for it. Do your prints warp, detach from the bed on their own before the print is finished, or curl? If no, there's no reason to solve a problem that doesn't exist.
