Are you planning on buying this? Or are you planning on selling? I ask because I am looking.
Seriously though, a new, re-pop steel tub from the States can be found for ~$2k-$2.5k. Fiberglass or kevlar seems to be about a grand more depending on the version of the kit you buy. The aluminum Aqualu tub is $4k.
I'm searching and trying to find one. For an excellent condition, OEM tub I could see paying up to a grand - depending. The one you mention has rust bubbles - without seeing it I'd say it might be worth ~$500 or so - again, depending.
The big problem with finding a good Jeep tub is the cowl area. If there is rust in the welded seams it is going to be a PITA to get out - if you care about such things.
There is a "rust free" tub for sale on kijiji right now but the guy selling it is delusional. I can see "surface" rust in the images and he is asking $2.5k. I haven't bothered calling him because at that price it is way overpriced and I doubt he'll move to a reasonable price range. At that price I'd rather spend the extra couple hundred bucks in shipping and taxes and get something brand new from the States.
I've got some feelers into the "local" pickup truck guys that bring stuff up from the States. I don't have any prices from them yet. I can share the information once I have some if you are interested.
HTH