Even if you pop for the new battery at $2200, that seems like a pretty good deal to me. The cost for a new car is going to be way more than that. A general inspection is a good idea, will provide some basic info you need to decide. Brakes, bushings, water pump, suspension, coolant, all that stuff is relatively easy to fix. As long as the routine maintenance has been kept up-- oil and filter changes —the gasoline engine shouldn’t be an issue at 125K miles. The key issue I’d ask the inspecting shop to check is the condition of the hybrid motor unit. Those aren’t easy to fix and quite very expensive to replace.