I usually see the bottom with the top and they are listed between 1100-1500. I have never bought one to flip because there is always 3 for sale when ever I look. IMO 700 is fair but I would try to barter at 5 and hopefully settle at 600. If you want to sell this box it needs to be pristine because a lot of home owners bought them and never put a scratch in them. Most of them that i have seen in shops don't look that great after a few years, that is in pics so they are likely even worse up close.
My personal advise would be to a get a KR5xx or KR600, i belive they are 33" wide less than 20 inches deeps, but they look like krls, have ball bearing slide, have great paint on them. Of course you would be adding a side cabinet or drawer stack. They are high value stacks bought one for 400 5 months ago.
There is also a kr660 it has 2 banks of drawers another bank of drawers, not as high space/$ as the stacks but it is a great box that fits your needs described. The cheapest I have seen them is 600 and they average around 1000.