I have not done business with them and have not really found any reviews when I did a Google Search on them but upon checking their website, they seem to be a legitimate company. They have been online since 2004 with satisfactory contact details on their website. They also accept safe payment through PayPal/CCs.
Here's an excellent article with tips on how to pre-qualify your supplier:
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You may also click on the 'Education' tab on any SaleHoo Page and view more articles on online selling, finding the best suppliers, protecting yourself from getting scammed, etc.
All the best,