Pete04 - see Post #3 - there is no "price". I am sure a "real one" would go for double to triple to the guy that has the matching serial number rifle, scope, scope can and rest of the stuff that was stowed in there. I have never bought or sold one, so just my wild guesses - say maybe up to $200 for someone who wants "one", or if genuine-ness is questionable, or if rotted or significantly damaged, or "repaired", or painted over; maybe $400 to $500 to someone who has the rifle and rest of the matching stuff that it originally came with? But I may be way out to lunch with those prices - am sure the pricing opinion is based on whether wanting to sell one, or wanting to buy one.
I do correspond with a guy who has had a really nice No. 4 "T" for sale on EE for probably more than a year - no credible offers when initially posted at $17k, I think it was; I think it has recently gone, though; it was almost, but not quite complete - something minor is missing - but includes "T" rifle, scope, properly serial marked for that scope, scope can, transit box, and so on - all matching stuff, all authentic, with good provenance from when it was bought out of DND in 1960's. So that was essentially all matching stuff, and was not broken down in price, piece-by-piece. I do not know of an example of a No. 4 "T" transit box sold on its own.