Once you are confident the supplier has been briefed perfect
you should order a pre-production sample. (Some suppliers
will refund this cost when you place a bulk order.) Expect to
pay approximately double your final selling price for this one-
off. This may seem expensive, but it’s not nearly as expensive
as ending up with unsellable stock.
Assuming you’re happy with the sample, you can place your
order. But how many to order? This is a difficult question to
answer as it depends on many factors, including:
-Your cash flow.
-Your attitude to risk. -Your experience.
However, it’s fair to say that most people test new products on
a relatively small scale initially- say 100 units. That’s high
enough to keep the stock purchase price reasonably low and
enough to get a reasonable number of customer reviews (and
traction) on Amazon. Remember, if you can make a profit on
your initial order, you’re almost guaranteed to make more
when you reorder in larger quantities.
A-Z of Amazon 