i think a good rule of thumb is:
if someone asked 'does anyone know where i can find a kit of the T-28'
then posting the link is acceptable.
if you showed us pictures of a kit you built and then said you had gotten it there,
either on your own, or in response to a question, i do not think anyone would mind.
we refer to commercial sites and enterprises quite frequently here,
but we do it
in the context of our discussion of building models
posting a site selling the tank completely out of the blue is too close to advertising
for most of our tastes.
if you are trying to draw a connection between this and DJ's post
about 1:1 AFV's for sale, you are wasting your time.
it is not remotely the same thing.
most of us here complain abt the cost of aftermarket goodies.
it is not likely that we will scamper off and drop thousands on an
actual military vehicle.
it should be fairly obvious that links of that sort are posted either for humor or reference.
and if you have not worked it out yet from the other responses,
i will tell you plainly: knocking heads on this subject w/ members who have
established a reputation as excellent modelers and helpful forum contributors is not going to be well received.
you really don't have a leg to stand on, and the more you persist, the worse you make it for yourself.