jjd - most application consultants will let you schedule 45 min. initial review sessions for free. I did these with 3 of the more well known consultants around and I decided it was not going to be worth it in the end.
Even in those 45 mins. you certainly get a good sense of how your future interaction with them will work out if you do decide to go ahead and hire a consultant. For instance, I'm just not willing to pay several hundred dollars an hour to someone who says she's going to e-mail me a document right after our conversation and then conveniently forgets all about it.
The consultants try to make you fit a certain profile, a profile that they believe will successfully get you into 1 of the 4 or 5 schools of your choice. They can also be dismissive of achievements that mean a lot to you personally, simply because in their mind a successful applicant should have done X, Y and Z and if you for some reason ended up doing A, B and C or followed a somewhat non-traditional, or "wonkier" as one consultant put it, path in your career then you aren't getting in into the top schools unless you undertake a 6 week long trip to Africa and work with malnourished children or the like. Of course, I'm being a bit facetious here but you get the drift.
So essentially if you already fall into the profile of a successful MBA applicant, you don't really need a consultant to begin with. If you don't, the consultants are, in my subjective opinion, going to try their darndest to make you fit that profile. In the end that's not who you are, and you can be sure doing this will make your essays look a lot more studied and a lot less genuine.
And in closing, I know this will raise some hackles, but some schools (Tuck comes to mind) expect MBA applications to subscribe to a basic code of "honesty and integrity" and want each applicant's essays to be "exclusively" their own. So depending upon your own conscience, you may or may not want considerable outside help with your essays.
Obviously no one wants to admit to having their applications crafted, fine-tuned, reviewed or whatchamacallit by application consultants, so I'm sure a lot of folks don't really want to "out" themselves by admitting to having used consultants. That said however, listen to what kryzak is telling you - there are a handful of extremely smart and helpful people on this board, and in my experience what you learn from your peers here on gmatclub is often just as helpful as the advice a two hundred dollar per hour consultant will dish out.