The only critique to this offer I have is that the retail value of the jewelry is no longer applicable. Assuming it's authentic, the re-sale value is unlikely to be evaluated as much (if any) more than the value of the precious metal from which it's made.
The sum of the price of the two items with the supposed discount is €568. I doubt that the value when sold will exceed €100.
When you buy investment gold, like a bullion, if you buy a 10 gram bar of gold today it will cost you about €596 and if you sell it after 5 minutes they will give you €555 (
source).
With jewelry it is much worse, since you are paying for the design and the brand, but when you go to sell it or pawn it you are going to be paid for the gold content by weight, and it is rarely more than 15% of what it cost you. The solution would be to find an individual who will pay you for the jewelry as jewelry and not for the value of the gold it contains to be melted, although you should also offer them a discount on the price in the store, but basing a loan on that has little hope of success. So, you are right.