You basically have 2 options here.. you either get the clears yourself with hard work or you pay for help. None of those people selling runs are going to do the content simply to help random new players. Friends or FC mates maybe but random people, not likely.

As for rmt I don't think you can place blame on the clear sellers since they're not the people buying gil. While I agree that it may give people a reason to buy gil in the first place, there are also a lot of legitimate players who buy clears, and the clear sellers themselves have no way to tell if the person buying a clear got their gil legitimately.