Avalon have not scammed people and has delivered ASICS already, however since they know this they have scammed in the sense of pumping next batch prices up ridiculously.
Yes 1 GHash=1000 Mhash (or 1024 whatever)
I am not a miner, but maybe you could use that GPU to investigate mining alternate cryptocurrencies such as LTC which is gaining strength lately.
I doubt you will make much money out of just 1 card (you could check see if you can find the hashing power of your card and then with a mining calculator get a figure of how much you could be earning), but you can get to know how it works hold coins and if LTC continues to rise who knows hey? maybe you will make a lot of money. Just remember the hashing power for won't be the same for btc than for ltc, this will be much lower due to the different characteristics of them, i felt into that the first time and thought omg im gonna get rich!
So yeah make sure you find the script (ltc) hashing power of your gpu, it will normally be expressed in KHash.