Your right in the ring i have bought from QVC was on the link you posted . I dont dislike it, in fact i do quite like it, but the amount of tanzanite for the money seems too good to be true. I have never ever bought such an expensive ring in the whole of my life, and i just need to be told i havent blown such a large amount of money away on rubbish.
I can't tell you what your ring is worth OP, I don't follow Tanzanite prices as I'm probably the only person in the entire universe who isn't that overkeen on it! lol (Though I can still admire good quality pieces bought by other people, obviously!)
Whatever its
actual value, you do need to remember that jewellery is a very subjective thing, what sets one person's heart racing may only have a shrugged 'whatever' effect on somebody else & like most things, is worth whatever somebody is prepared to pay for it, to get that particular design, colour etc.
I have never, ever bought a piece of artwork, pottery, whatever, on its value alone but rather because I liked it &
wanted it & consequently, have sometimes paid far more for things than their actual, intrinsic value.
Having said that, nobody wants to find out they have bought a very poor quality example of something but all things considered, price is not the be all & end all if you love something!