If you have no current storage, I don't think it's a bad deal for half of what he's asking. Try it and see. If you keep cruising CL, you will eventually turn-up a good deal. You should be able to get a good used set of boxes for not a lot of $. Make sure all the drawers work well, as you may not be able to get parts to fix a drawer that is no-longer supporting a load. Depending on the amount of space you have you should look at the Sears closeouts at your local stores, each store will have different sets or pieces. You just have to keep going back time & again.
If you're looking for new, Whirlpool has a line called Gladiator which is well-built, and should be available thru your local Big Orange Box Store. Sears also carries it. I have a half-dozen of their 30" X 30" X 12" wall boxes, welded steel, powdercoated, hung on my masonry garage wall w/tapcons. They are very functional, strong, and have 2 movable shelves.
I think this one would be a good start:
https://myrtlebeach.craigslist.org/tls/6197017241.html
Looks like a box-construction ball-bearing drawer design 41" long. Asking $200. Offer $160. Make sure it all works flawlessly, if not, thank him for his time and leave.
There are also online toolchest vendors that may be worth a look-at.