catfish
Riding an Alexander Rocket Bike
Bike looks pretty nice. It does have a coaster brake and appears to have ball end spokes at least on the rear hub, I can't see the front hub. I'm a little surprised by the leaf spring saddle because that saddle may be a little older than the bike but maybe not. I'm not sure when leaf spring saddles fell out of favor and wire frame saddles became more predominant. I think the year listed on the bike 1902 is pretty close but I will let a Columbia expert make that final determination. If it's all in good shape you can expect it to be worth more than $1000 and less than $2000. It's up to you and the seller to decide where the in between is the final price.
If the hard rubber tiring tool on the ground below the rear wheel is for sale, in complete undamaged conditon those typically bring between $100 and $200 so might as well try to purchase that as well.
Good eye! Have him throw in the tire machine as part of the deal.