its pretty much the same thing as dkp however the only difference is you use a division instead of subtraction to get current value. hope it makes sense!
That is indeed the fundamental difference between EPGP and DKP. EPGP has it's own subtle differences, such as the auto-pricing of items and the specific decay mechanisms.
The auto pricing is something that I've been planning and will have two conditions:
1) It shouldn't be exclusive to EPGP
2) It should be completely customizable by user-specified formula. We would, of course, provide a default formula for items.