If you know you are in 17min 5k shape, then why do you need to gauge your fitness with time trials? You already know what you are going to run. Two options: do the time trial on your own since you're not in great shape anyway it won't kill you, or hook up with a local running club and do a workout with them, OR suck it up and show some respect for the local running community and the people measuring the course for you and providing you competition (if that is so important to you) by paying the race entry.