I got to Cat 1 without a coach but I did get a lot of good (and a little not so good) advice from more experienced riders and racers. I wasn't afraid to ask a lot of questions to the guys I ride with. I raced a lot and I spectated at races to learn how to race well (which is different from riding well).
As mentioned by the other guys, there are several good books to use as a resource and lots of online information. A power meter and HR monitor would be great tools in helping you pace your intervals. I'd invest on those before I'd pay for a coach.