Hello and welcome to the forums
I've moved your post to an appropriate forum...
Re these Amazon Marketplace deals, there are many threads that discuss this... Here's one of the more recent ones:
Amazon marketplace deals - too good to be true? - PentaxForums.com
They are almost certainly scams. I went part the way through ordering on one example offer, just to test it out - and I ended up being asked to contact the seller via an e-mail address outside of Amazon - which is exactly what I expected. Had I proceeded, this would then move onto payment outside of Amazon, and a long... long... never-ending wait until I finally realised I'd been had.
Run a mile, that's my advice