Hi,
Trade secret time...
We use Certes Auction Intelligence when working with our agents. We give them a complete data analysis of any product we're bringing to the UK. For example, we specialise in brand new niche accessories for consoles... and everyone knows the first guys to sell these are the Hong Kong sellers, with their elastic postage prices. We enable the UK sellers who buy from us to get in even lower than the Chinese sellers, and plaster a UK STOCK slogan all over the item
Anyway, we punch in the product, and we extract info like how many are selling in the Uk, what the prices are, when they are selling, what the postage is, what the keywords are, and just about everything else... It is a massive heads up for any product. We ship in based on the results, its that simple.
If you're unsure, give it a trial. We've tried a few, and this came out on top.
Hope it helps