Well, without knowing dimensions of the box, or what particular model it is... I'd say that box is roughly around $5,000 brand new (judging by comparable models in my snap-on catalog.) $5,000 being a very low guess.
Dependent upon the condition of the box (obviously), and what tools are actually included (pictures of 3 drawers doesn't even cover 25% of the drawers), this could very well be a good deal. Especially if the box is in good condition, and the tools are decent as well. My advice would be to get a look at the box in person, and check out all the tools that are being offered. If you decide to though, I'd hurry. If it is a good deal, it won't last long.
Scott