I work on video games where I need quite a beefy graphics card, I could have gone with the 980/ti but it made sense to hold out for a week for the 1070 release.
to be fair, if you really earning money from this you should ALWAYS ALWAYS have a spare. even its a cheap 750TI.
if you saying your earning money from this every minute you not working is loosing you money which would not be loosing if you owned a second card even if it was a 750ti or lower..