Look for some advice on Sub Zero 736-tic-3.

I have a higher end rental unit. A family friend also just so happens to be renovating their kitchen. Their appliance store offered them a few grand on trade so he offered to sell me the appliances for same amount.

36” bottom freezer sub zero. Built in 2007 I think. He wants $700 for it. He does regular maintenance on it but this isn’t his primary home either.

My question is, is this thing going to bankrupt me in the long run? What do they cost to maintain and repair? What typically go wrong etc… any advice appreciated.