With latest PIC programmer pricing, it just doesn't worth to create it. However, PICKIT 2 is a kind of open source (at least 100% on the PC end), they give the bootloader .HEX and the related schematic, so you could build it yourself... but I don't believe you'll beat the already assembled pricing (~40USD$).

Look at Bluerooms electronics JuneBug, which is a PICKIT 2 + nifty development board.
http://www.blueroomelectronics.com/Junebug.htm

There's also load of clone available, but the pricing is not that much under a Genuine Microchip one, and some have their own issue.. as per we see on some forum here and there.