Editing services are all over the Internet. The key is to find someone who can do it for a low price and in the time frame that you need. Many freelance websites and writing websites will provide editing services and in many cases, you can choose the price that you are going to pay. When you choose a freelance editor, you can usually request a freelancer to write a proposal with their prices and deadlines, so you know exactly what you are going to get.
While you might have difficulty finding an editing website, you will certainly have an easy time finding a writing website. You may not realize it, but each writing website will have people who can edit any paper that needs editing. These websites usually charge reasonable fees. But it is important that you know what you are paying for, because many of these websites will employ writers who are not native speakers. If you have a non-native speaker edit your paper, it will not have a natural flow that native English speaker have.
You should also be sure that the online help that you receive will be able to provide a second round of editing at no extra cost. Most writing website will include at least one edit; so if you are requesting an edit for a paper that you wrote, you could easily ask for a second edit, if it is needed. You should also see if you can choose the person who will be your editor, especially since many writing websites (at least the good ones) will allow clients to choose their own writers.
There are also many freelance editors who will work via video conferencing with clients who need papers edited. If you are working with a freelancer, ask if the freelancer will help you in a face to face conferencing session. This is a great way to figure out what you needed to have fixed and why so you can find the errors the next time and not have to hire anyone for editing. If you cannot work with a freelance editor via video conferencing or other messaging programs, you might be able to work with a college student in an IM setting so you can both communicate immediately with each other.
You should not have any problem finding editing services, especially if you switch your search to writing services, instead.