Every Awazon vendor page shows a deal count and a dispute ratio at the top. Read both before you order. It takes about a minute and it is the difference between an informed order and a hopeful one.
A high deal count over time is a vendor the market has watched work. A low dispute ratio is good, and a rising ratio on recent orders is a warning even on a long clean history. New vendors are locked out of finalise-early until they have run clean orders, and the profile shows their standing.
If the numbers look off, choose a different vendor. There is no shortage.