The issue is, when clubs get so much income from ticket sales, no club is going to want to do the honourable thing and reduce their prices without all the others doing so, because they'd be leaving themselves in a poorer position to their competitors.
Some clubs have had a go. Bradford and Hartlepool have both tried this, and in Bradford's case cheap season tickets have proved very popular to the extent that net income remains the same. Hartlepool's scheme is embryonic.
About 20 years ago a then Division 4 Cardiff tried a pay-as-they-play system where ground admission was linked to their league position. It was only a couple of quid if they were in the bottom half, and went up on a sliding scale. they got promoted and attendance improved dramatically. That would have less of an effect now given the vast increase in season ticket sales at most clubs, but it's innovation that should be considered.
Look at it this way: at every United home game this season bar one, the likelihood is that there will be at least 10,000 unused seats. Personally, I think it's folly not to consider ways to fill them.