In my opinion, no. If you are going to do it, do it right. It is an investment. Tackle it from the outside.
1. Water will always seek the path of least resistance. So, even if you coated that side of the wall, the water will build up and seek an alternated route.
2. Since the water will build up behind the area coated with epoxy, the pressure will also be building-up, creating what is called Hydrostatic Pressure. Which in time will just pop the epoxy from the wall.
3. If you do not properly prep the concrete, the slightest pinhole will be the weakest point.
Can you reroute the water to flow away from your house?
There are different grades of epoxy and hundreds of formulations of epoxy for different applications. Most of the epoxy products sold in Home Centers are very cheap in quality. Most of the store bought epoxies will sit on top of the concrete instead of seeping into it.
There is a product called Hyrdo Block from Surecrete that I have used with success. It works by bonding with the concrete on a molecular level, forming a barrier. Again, the surface must be properly prepared.
Do yourself a big favor and have the mold tested and the house inspected before you decide to buy the house. I don't want you to end up with buyer's regrets when remediation could cost you a lot of money.
We just performed remediation work on a house that had mold that the homeowner thought was just in the basement, but we had to take down most of one outside wall due to migration.
Good luck, any questions- [email protected]