Well, since you're the person selling it, you'd probably know if anyone bought one, and you could ask them directly to post a review.
Barring that, you say you can't afford to give one to reviewers - why not set up a passaround, and try to get several of the reviewers to join? That way you'd only be out the cost of postage to the first person on the passaround list, you get a group of people who probably wouldn't buy it without knowing more about it to get their hands on it and form an opinion, and you could get some known/respected reviewers to give their opinions, good bad and ugly.
In fact, as you unleash a series of new products, that might be a really good idea for you - and other vendors.
Find several items that fit in a common-sized box, and offer them up as passarounds. That way you're only out one copy of each item, only pay to ship them once, you get exposure and get the items back.
Dave