The basic extrusions cost about 50¢ per inch and the connectors cost between $6 and $35 each. The main brand of T-slot extruded aluminum is 8020. I'd been researching different cabinet building materials in vans and kept coming back to folks that use extruded aluminum T-slot, due to the overall look and the strength to weight ratio. The upper cabinet for this latest project is a little different in that it has fewer attachment points to the van and does not touch the floor. The majority of our Sprinter van build structure so far has been done with 3/4' plywood and no 8020 aluminum extrusions.