| Factor | What to Check | Why It Matters |
| Buyer reputation | Reviews, years trading, a physical address | Reduces the risk of unfair deals |
| Grading report | Whether it’s available, recent, and matches the stone | Supports a stronger offer |
| The 4Cs | Carat, cut, colour and clarity | Drives most of the resale value |
| Offer breakdown | Whether testing or handling fees are included | Shows what you’ll actually receive |
| Promotions | Whether a bonus has conditions attached | Seasonal deals can hide lower base prices |