It seems like something that could be done with little fundamentally new technology. Demonstrating the real-world application of the synthesis and use of fuel off-planet would be a major milestone in space exploration. To top it off, bringing back the first samples from Mars would be a major feather in the cap of any nation or corporation.
To me, getting that set of technologies to an operational level is one of the biggest reasons to go (back) to the Moon. It's cheaper to send demonstrators there, and easier to troubleshoot them.
Once we can do ISRU refueling reliably, the solar system will become dramatically more accessible (to robots, and eventually humans).
You'd have to use a completely different type of ISRU for the Moon, and mining for it on the Moon (i.e. scraping a permanently shadowed crater near a lunar pole) is a lot harder than on Mars where you can just suck in some of the atmosphere. There's not nearly as much commonality as you might think.
The only equivalent option I know of for the moon would be to collect water ice and break it down to oxygen and hydrogen. The process involved would be quite different.