vapor barrier that is sealed on the interior walls

There's your problem! Get rid of it!

Though I've used them in basements, I would be cautious using metal studding. It's clean and fast and doesn't warp. But it is susceptible to moisture, galvanized or not. I've torn apart renos done a few years before where the bottom plates were already rusted out. Keep the plate off the floor with an inch of XPS under the plates and be sure the walls are either foamed or covered in sufficient foam board (XPS or EPS) to slow moisture movement and keep that dehumidifier on.

Read the publications at Building Science (linked below). There are no higher authorities.

Here is a link that might be useful: Building Science on Basements

My contractor suggested that I only needed the standard blue board, wood studs, and fiberglass insulation.

No fiberglass, unless it's to the interior of foam or foam board. Or, perhaps, you're using Membrain vapour barrier, which is very difficult to find.

Again, see Building Science publications.

thanks, helpful!

It sounds to me as if you used the wrong approach to eliminate dampness on your walls. Interior water-control systems cannot eliminate dampness of the walls.

You will only accomplish this with actual waterproofing. This requires excavation to the footing. Rpairing cracks, sealing the walls, installing drainage, and backfilling with gravel.

Most interior drain companies claim to be waterproofers, but all they basicly do is control the water once it has entered.