Advice on buying and resizing solitaire ring from Costco

[curiousgem19]

Hi all,
I Am a new member on PS and need your advice on buying a solitaire ring.

I have been shopping around for a diamond solitaire at different jewellery stores and by chance, came across a beautiful, simple ring at my local Costco (of all places)!!! There wasn't much information available about the ring except a small tag attached to it that said:
Platinum, 0.5CTW, VS2, I, round solitaire diamond ring, $2100

I came home and have been scouring the internet, trying to find out more about buying diamonds from Costco. To my surprise, there are a lot of favorable things being said about buying diamond solitaire rings from Costco. So, I am seriously thinking about buying this ring from my local Costco.
(To look up additional details on the ring, i went to the Costco website, but this exact 0.5ct model is not sold online...But I did see a 0.8ct ring with very similar specs to the one I am interested in: http://www.costco.com/.product.100035131.html
Another minor difference is that the 0.5ct ring I am interested in has a setting with 4 prongs whereas the 0.8ct ring in this above link has 6 prongs)

Also, all of Costco's rings in the store come in a standard size of 7, whereas my ring size is 5. Costco does not do resizing.. So I will have to find a local jeweler for this purpose.

So, here are a list of questions that I have:

1) Based on these specifications, do you recommend I buy the ring from Costco?
2) Does this price seem reasonable for the quality of the ring? Or is it overpriced?
3) How easy or difficult is it to downsize a platinum solitaire ring from size 7 to size 5? Will a welding line show?
4) will the setting of the solitaire (4 pronged) become loose due to the resizing?
5) how much should I expect to pay for a resize?
6) does anyone have any recommendations for a good place to get platinum rings resized in San Diego?
7) does anyone have any recommendations for diamond appraisal in San Diego?

Thanks in advance for all the help!!
Really appreciate it

 

[AprilBaby]

It could be a great diamond or it could be a dud, you are missing the most critical information:cut. That is the true test of how sparkly it will be. You have no measurements at all. It can be resized anywhere, you should not see the sizing. Will you be happy that she says " he got my ring at Costco?" Some women mind, others don't. Around here a resize is about $75 per size. A four prong should hold the diamonds fine.

 

[motownmama]

Why not call Whiteflash and ask about the best diamond (about 1/2 ctw) in a platinum 4 prong setting, so you have something to compare.Would be better to have a GIA graded stone. Good luck!