The box is not a newer 6s, but it is basically the same. For about the last 20 years or so, matco has made same basic box, they just change the model numbers every couple of years. It has the standard casters so the box would be between 21" to 24" deep. Not a bad price over all, I'd try to get it down to $1500.
In my opinion, No, it is not a good price. A good price would be a $1000. I sold an entire shop at one of my auctions the first part of the year and sold a Snap-on box like yours for $1280. and I had 9 people bidding on it. Boxes are a dime a dozen. Everyone is selling them because they can't afford them. the problem is that they only sell when they are cheap. A huge 9 thousand dollar box sold on E bay this year for $2289. That was in NJ. I would have bid on it but it was to far away to go pick up. I would say !200 is the most I would pay for that box if there are no dents or scratches.
I picked up a 42 inch Matco box that was 24 or more inches deep for $500. It had a long drawer on top. I gave it to my Grandson. It had a row of wide drawers and a row of narrower drawers. They are out there. Keep looking.