The site does seem legit. But since we at SaleHoo have not dealt with them previously and personally, we cannot guarantee their reliability as a supplier.
We did try and do a quick background check for you and so far we were unable to find anything negative about them on the net. They have been online for a little over a year. Ideally we would recommend suppliers who have been online for at least 2 years. Their ordering system is quite different from most suppliers since you'll be able to inspect the goods personally before actually paying for it, so this could be a benefit. But then again paying with cash also has its draw backs since you wont have any way of getting your money back if the deal goes sour.
Also another thing that may raise a concern is their contact email, most legit businesses will have a domain based email address and not one from a free email account.
Hope this helps. All the best to you, we hope everything works out well!