How many times printed printer can print it-self?
Photo Credit: Courtesy of 3DStockPhoto ( image)

As long as you maintain each printer and keep a proper calibration, go for it, this is what they were designed to do, I've even made replacement parts for myself.

Unfortunately the RepRap project just shut down on 1/15/16 due to their lack of sales.

I have a reprap that came from a reprap, and has made another reprap.

Just make sure that when printing out the pieces for the next you are properly calibrated, otherwise the next machine might be built crooked;

Your only limitations will be the electronics pieces and the small amount of hardware that you will need to buy.