If this was me, personally, I would get out of this as fast as humanly possible while ensuring I did not take a financial hit.
Was this transaction Fulfilled by Amazon? If so, you can easily return it for a refund and not even have to pay shipping. If no, did you make this purchase on a credit card? (i.e., a payment form with Buyer protection.)
If this is a 2016 model, $115 off Apple's current price of a 2017 model is an absolute terrible value. The 2017 is significantly faster, has an improved keyboard, and gets better battery life. If it is $115 less than a new 2016 model, that's still not a very good deal because, A) you may be buying someone else's problems (for example, this could be a model with a keyboard issue that the original buyer did not discover until they were out of the 14-day return period), B) that discount is less than the discount you get purchasing a refurbished model, and C) the Seller is either incompetent or dishonest - and either way that's not a good thing in terms of the Buyer-Seller trust one wants to have with such a big investment.
If the Seller refunds you another $200, give or take, then it might be a better deal worth sticking with.
The system is still eligible for AppleCare+ for another two weeks, if you plan to keep the machine (and IMO common sense with the 2016 MBPs, and even more so in this situation.)