Yes.
You can return the item for a full refund as Item Not As Described.
You may have to open a Dispute in the Resolution Centre if the seller is not cooperative.
You will be required to return the item to the seller before being refunded. Use tracked/Confirmed Delivery shipping.
But a 50% discount is not unreasonable.
Many sellers here are selling close to wholesale, or refurbished items, or end of line.
The markup on jewelry in a retail store runs about 400%. Which means the item your local jeweller has for sale at $100 cost him (not counting the overhead cost of running his store) about $25.
If he wants to turn 'stuff' into money, he could sell it for any amount over $25 and still be ahead.(Not counting overhead, of course.)
Overhead costs of selling on eBay are very low, only about 20% of the selling price of most items.
