What should I offer?

Start by showing him the KBB. Then ask why he feels $2000 is fair. Is there a kick-*** sound system, modifications or up grades, extras? What is this additional $875 for? Now be careful. 193k is a lot of miles. This car is worn out unless it has had all it's regular maintenance. Ask if he has any receipts or maintenance records. I'm not just referring to things like changing the oil, the air filter and wiper blades. Were all belts and hoses replaced a 50,100 and 150k and the system flushed? Where the front wheel bearings and seals inspected cleaned or replaced at 100K? Check all functions of the automobile. Every knob, switch, light, hinge, button, dial, function and is everything that came with it new there? The jack, spare tire, owners manuel....ect. If you find yourself questioning anything twice, PASS ON IT. $2000 is too much, hell $1200. And 193k is a tremendous amount for a Chevy Blazer. Remember in CA. the seller is responsible for the smog test and certification. If there not willing to do that. This is the RED FLAG you'll be burying this car in with all your money. Regards, Greg.