There is a massive difference between dollars produced and proof of work performed.
Calculating by dividing its "treasury" by number minted its value is computed and posted to the
Latest Rates include-file as I write as GRPrate=196.85817921 DeVCoins.
One can tell the file is denominated in DeVCoins by finding the assets shown as 1.0000000 ; the values can all of course readily be converted to use any of the others, or any arbitrary value, as unit of account.
DeVCoins themselves of course are also a "treasury-based asset", its calculated value can be calculated from any of the other treasury-based assets on the list, which I think are usually just BTC, LTC and NMC.
How many dollars anything works out to in practice tends to vary according which spot markets you obtain your buy-side asset from; going to FreiXlite to obtain DeVCoins for example would cause a far different set of values. So basically one can run around from venue to venue seeing which asset you can get at the lowest (price divided by calculated price) to figure which one would be most cost-effective to use if you want to figure how far off from calculated values you can pick stuff up for as it were.
GRouPcoin is merged-mined but I am not sure if anyone or manyones do that anymore.
Which reminds me a glance at the fpool link you provided makes me suspect it is not that distributed-mining distributed-pool we used to use, maybe I am forgetting that distributed one's name thus confusing it with fpool which my mind somehow has the impression was the distributed one? Or is it in fact that one?
-MarkM-