Sight unseen and no inspection...it would have been wise to ask someone about the soundness of this action.
Our recommendation, as others have mentioned, is to consult an attorney for their advice.
Have you spoken with the agent?
I've solved a big water problem in my basement with little money. I made sure the outdoor run-off was drained away from the foundation by grading the dirt to pitch away from the foundation. Plain old black plastic buried 4" under the dirt works wonders. I later was able to prevent the occasional rise in spring ground water from bubbling up on top of the cellar floor by digging a very small "ditch" 4" to "6" deep x 3" wide around the inside cellar foundation to catch the water before it reached the floor. This water trench was directed to a hole , about 1 1/2' X 1 1/2' for collection. You could then pump it out. In my case, I was able to send it to a drain.
Exterior excavation and perimeter drains are an unecessary major project in my experience and I own several properties. And, if the grading isn't done properly as described above, it won't work well, if at all, for the surface water. The epoxy fix is also expensive and offers poor temporary results. The best and easiest solution is to prevent surface water from reaching your foundation walls in the first place by exterior grading of the dirt, plain and simple. Inexpensive with your own labor, neighborhood kids or modest costs hiring a landscaper.
Best wishes, Len
Did you use a buyer agent or a seller agent to buy the home? My guess is the buyer's agent would have less knowledge about the home and this specific problem in the past.
Did you read and initial a seller's disclosure statement? What did it say? With that, it's all about plausible deniability. Maybe the seller didn't have any leak issues- and the owner before him might have. So in that case, the seller didn't think there was any concern with water leakage- ?? Just a thought.
I know its water over the dam (no pun intended), but for $300 I always recommend a home inspection- even for a brand new home.
You should call someone that does epoxy injections to fix this problem. Most likely this is your best and easiest fix. Will cost you between $600- $1500 most likely. I've ordered many of them. If you need any further help, please let me know. Thanks, and good luck,
Best of luck to you