My lighting/electrical distributor has a bunch of NOS 90w and 55w SOX Wallpacks available, I believe they were Lustra brand. I took one out of the box and opened it up, they come with a Philips lamp pre-installed. The fixtures themselves are very large, the 90w is at least 36" long and have a glass refractor/lens. They are asking $50 each for these (both sizes), and will not budge on price. Is that price worth it?

Considering that the lamps themselves cost that much to buy new, I think they're worth it.

i would say it a deal . cause ballast hard to find now
as philips already stop manufacturing ballast.  second
got about year left  as philips going end manufacturing
of lamps. yes now days in this world it a deal. infact I am
interested in a 90 watt sox wall pack. I have loads of spare lamps and no fixture. PM me please.

YES.
Would actually look into getting some if I knew where they were.

I would deff get one of the 90w for that price!

how heavy are they?

Wow that's a deal, would you be willing to pick one up for me? I'd give you extra for shipping and the time to go get it

Would you be able to have them shipped from the distributor? I might be interested in a 55w fixture.

Pity they're not nearer to me, I'd love one 

You haven't mentioned your location, but on the off-chance you're in the US, I'd happily pay you $100 plus shipping costs if you want to flip one.