You literally cannot compete without a coach-- it's against the rules. Jumps and advanced spins are complex and sometimes counter-intuitive. Trying to figure them out on your own is ineffective and not safe. Having another skater who is not a coach help you is, um, ineffective and not safe. Having another skater who is a coach help you is exploitive. Here are some options:
Take every class you can find
This is easier, obviously, in a large market. In any market, if you're an adult skater you're likely to have to take Freestyle 2 with a bunch of 8 year olds. Unless the rink specifically prohibits it, (some do), just go for it.
Every rink I know allows coaches to do lessons with two kids at a time; many allow 3, and some even allow four or more.
Space the lessons out
And ask the coach for week-by-week goals and to designate some milestones in between. You might be able to get away with a lesson every 2 to 3 weeks. Be prepared to be extremely flexible, however, as the coach is going to give priority to her regular students.
By the minute
See if a coach will give you ten- or fifteen-minute single-skill lessons. It will be slower, but this is actually remarkably effective.
Do you have a desirable skill? Set up the coach's website, or do his books, or I don't know, mow his lawn.
Get another job
People do this, but it doesn't have to be drive a bus on the overnight shift. It can be make skating costumes, or work in the concession stand a few hours a week.
Make the kid get a job.
Many teenaged skaters do this.
And then blow it all at once-- spend six months saving for three months of lessons. In the interim, do some or all of the things above.
It's an expensive sport
Finally, there is actually the option of not taking lessons. This is an especially difficult decision to reach if you have to tell a talented child who loves to skate that you can't afford it. But it's another reason that I love skating-- it's an amazing place for life lessons.
What have you done to help with the cost of lessons?