Thats right but with only one card.. for example my asus radeon r9 280x... with 1000Mhs (script) you will get around 0.005
True - I'm not sure what the correlation between 1 Mhash/s scrypt (and then, which flavor of scrypt) and 1Mhash/s heavycoin mining is, so they would probably be better off running a miner for a few minutes, check their actual hash, and go from there?