
There is a very real reason to pay attention to price when selecting an academic writing service:
quality. It just makes sense.
The companies that work with freelancers who are not native English speakers, or who live in places where the standard of living is low generally pay very low per-page rates to their writers. That means that the best writers are not going to be interested in working with those companies. So, the price might be very low, but the quality will be commensurate.
On the other hand, companies that charge high rates tend to offer products of much higher quality. Those companies can command the services of freelancers with far more experience in the academic writing profession, as well as freelancers who are native English speakers.
Now, high prices don't always mean higher quality, and lower prices don't necessarily mean poorer quality. Having said that, just as in every other business, prices in the academic writing world tend to correlate with quality: in general, the more money you pay, the better the quality. After all, there is a difference between a Porsche and a Ford Pinto :)