Adult learners are very discriminating when it comes to instruction. Adults want quality instruction from high quality instructors. If the instructors are inadequate, the learning desired is much less likely to occur, and the interest in future courses will wane. Checking the evaluations and reviews on instructors is wise to do.
Again, a program may be less expensive because it has a less-skilled teacher. Try to learn how good the instructor is from those who have previously taken the classes you seek. There may be, but there may also not be, a trade-off between cost and quality of instruction.