Obviously, when Walt shot two of Gus' trustworthy men in Breaking Bad, Gus wanted to kill Walt and have Gale replace him after learning his formula.
However, around the time Gus offers Walt '3 million dollars for 3 months of your time', did Gus plan to continue doing business with Walt after these 3 months, or was Walt just a disposable source of money? At this time, Walt wasn't seen as much of a threat (he wasn't as much of a liability as is in series 4).
So, is there any evidence to suggest that Gus planned to kill Walt (or not) from the start?