i don't know how many api calls are permitted at nzbs.org/dognzb/gingadaddy - but at nzb.su there are 5000 allowed per day

if i take my 200 per day as a calculation base, and keep in mind to still have a decent amount of backup-calls i wouldn't see a problem to put 15-20 people on one account - but still don't know, if they lock a ip adress to the api key- if they lock it, you may have to install a proxy server, but this doesn't takes long and a hosted amazon aws machine/VPS shouldn't cost more than 15-20$ a month

and i think 1-2 BTC for a api key would be a fair price for both sides, if your refund/new account policy is still in place

or if you are a bit into programming, it wouldn't be a problem to code your own proxy service, to access all of them with one key...

so - i would offer 5 btc for a api key bunde of nzbs.org/dognzb/etc..