I would never buy new, because it carries such a high premium. The mark up on jewellery is horrendous.
Try good quality antique shops. No VAT on secondhand goods, and vintage/antique styles are more unusual than modern stuff.
I got some gold, ruby and diamond earrings for just over £100 in an antique shop, so I'm sure you could find something stunning and unique for £1000. And it would be more fun than schlepping round Goldsmiths and Ernest Jones.