Why waste 20 minutes of a professional developer's time, multiplied by the average number of reviewers, with a bonus for bad advice due to inexperience?
You know those clients who think programming is easy? Writing and reviewing copy is hard. So is pretending that you're an unbiased fresh-minded user, in a group of novice reviewers.
1) Tell me what you think the site is for. 2) Is this site attractive? 3) Try to perform task X, cancel before it asks for credit card info, and tell me what the most annoying thing was. 4) etc.
Send them several sites to review, including yours and your competitors'. Save $200 or heaps of everyone's time. Or pay a professional.