Should I buy 2012 Tahoe

Help with Used 2012 Tahoe

Within the next few months I plan to buy a used 2013-2016 Tahoe with 75k-110k miles. I was planning to owned 10k-18k depending on the deal I found. I found a mechanic selling a 2012 Tahoe ltz with 135k miles and got the price down to $6,100. The exterior and interior look great. It’s the original transmission but felt fine test driving it. Even if I have to replace the transmission within the next year or two it still seems like a good deal? It was not an old police vehicle. Any advice would be appreciated.