
Hi Somasu:
I would categorize writing services and academic writers working as ghostwriters into the following categories:
1.
Custom written from scratch - you give the writer the topic and, perhaps, suggest some references, and let them go to work. usually your most expensive option.
2.
Editorial services - you write the paper (or partial paper) yourself and then have the writer help you. it can be as simple as having the writer check for grammar and spelling mistakes or more complicated, such as having the writer integrate several different bodies of work into a coherent whole.
3.
Some combination of 1 and 2. #3 tends to be a less expensive option (per page) than #1 but more expensive than #2 because the writer doesn't write the complete work (to edit pre-existing work will generally be less expensive than to write it from scratch). of course, both #2 and #3 requires more effort on the part of the client.
4.
Pre-written essay papers purchased from essay banks. you just buy a paper that fits your topic from someone. since this is not a custom service, it's possible that hundreds of copies of the paper are floating around in the ether. the upside is that it tends to be less expensive. i don't know much about this option personally.
I hope that helps!