If anybody's looking to get cheap jewelery made, I'd advise them to avoid the Ernest Jones' in the St. James Centre. When measuring me for a ring, they managed to get my size wrong by an entire two sizes (almost an entire millimetre in diameter). Two resizes later, it still wasn't right, and the third time I went back, I was told that since it was over a month since I bought the ring, they would have to charge me. The price they quoted was 12% of what it in the first place, which I was understandably not happy about.
In fact, it's probably wise to avoid high street jewelers entirely. I took my ring to Alistir Wood Tait on Rose Street, who took the time to measure my finger properly, using a selection of real rings of a similar shape to mine. (He was amusingly Ollivanderesque about it — "How about... this one? No, goodness, that won't do at all!") When it was back from resizing it fit perfectly, and he charged significantly less for it than either Ernest Jones or H. Samuels were wanting.
Randomness: Kitteh vs. Potato! (Video)
In fact, it's probably wise to avoid high street jewelers entirely. I took my ring to Alistir Wood Tait on Rose Street, who took the time to measure my finger properly, using a selection of real rings of a similar shape to mine. (He was amusingly Ollivanderesque about it — "How about... this one? No, goodness, that won't do at all!") When it was back from resizing it fit perfectly, and he charged significantly less for it than either Ernest Jones or H. Samuels were wanting.
Randomness: Kitteh vs. Potato! (Video)