HDPE (high density polyethylene) is "plastic"The last line under the 'Description' section for this item on the LCI website shows this to be an "AbilityOne Product". I'm not sure exactly what that means but I bought a MWC from Grainger a couple of years back that was stamped "AbilityOne" and "Property of US Government:". IIRC, the price was somewhere between $25 and $30 out the door. Good can and I have no complaints BUT it is not of the same quality as my Scepter MFC fuel cans. The molding seams have a fair amount of flash and the bottom is not as uniform. Grainger carries both AbilityOne and Scepter and this is a comparison link from the Grainger site. The comparison shows the construction material to be 'plastic' on the AbilityOne while the Scepter is listed as HDPE and there are some slight variances in the dimensions.
This is not a knock on the AbilityOne product; mine has stood up to a lot of abuse and the price found by the OP is certainly great. If I had it to do over, I'd make the same choice.
LCI is the manufacturer, "Ability One" is a program to employ the disabled.
In the following photos the LCI can is on the top or right (note HDPE material marking on the bottom of the LCI can) I don't have a scale handy but there is no perceptible weight difference or obvious variation in manufacturing quality. They are both manufactured to the same mil-spec and both has NSN numbers
ETA :the image is flipped in the next to last photo, the LCI is on the left, it is the darker green can in all of the images.