My daughter has an education degree and teachers in and around the Denver area start between $33k-$39k and get few and far between raises. I,too, believe teachers, especially early in their career, work more 'off clock' hours than are being reported although many other professionals also work a ton of 'off clock' hours, too, so not sure if teachers are working more or not. I think teaching is an invaluable profession but it doesn't, in general, attract the best and brightest. Compensation is a huge issue but so is lack of incentive to be a great teacher as you won't earn any more than one who does a half-*** job.
The union has damaged education, imo. Ridiculous benefits in many states, retirement pensions that can be gamed to artificially increase a teacher's pension, almost no fear of ever losing your job (may get transferred to another school but outright fired is a rarity), raises/promotion based on seniority vs. quality, bloated administrative staffs (especially at university level), etc. The hackneyed notion that 'all we have to do to improve education is spend more money' is a complete joke. The US already spends more per student than almost every other competing nation and we get much less for our dollars. Surely, we've learned our lesson that throwing more money at a problem NEVER solves the problem (I know, I'm a dreamer). The whole public school system needs to be rebuilt but the union will never allow it. Our current system will continue to fall further behind the rest of the world as we spend more and more money on it.