If your permissions can be set correctly it is a simple painless process to upgrade to threads. I have done it myself many times and I am no expert by any means. If you pay someone you will still need to deal with your host to correct permission issues or add mysql to your hosting package if they are incorrect.
Depending on how big your forum is all it takes is some time to backup and upload some files.
You can always do a trial upgrade and see what happens. Then pay for support if you have issues.
