I agree the prices are a joke, but I would expect it to be a good few seasons before we started to see a significant number of empty seats due to bad performances.
Football seems to be more popular than ever and the clubs and owners know this and are happy exploiting fan loyalty. Not just Everton but at nearly every club. They know they've got leverage on us all because with so many thousands not even able to get tickets each week, anyone who takes a stand and doesn't go will be easily replaced by another fan willing to pay.
Look at the demand at West Ham, they even hate their new stadium but have been selling over 60K tickets each season. Be interesting to see how long it takes them to start staying away. I suspect it won't be too far off as they did recently get the European Trophy and a couple of top 7 finishes to delay the fan unrest.
Not sure in long run demand will last, Premier Leagues model was once top 4, then you had clubs trying to get into top 4, Villa, Everton, Newcastle, Spurs, then City. Then you had clubs who had UEFA cup ambitions Bolton, Blackburn, Fulham, West Ham and you had those smaller clubs trying to stay up. Also game was still mainly a working class support, and it was actually enjoyable to go to games. GP was only full because we sold ridiculous amount of season tickets and there was only a select amount of tickets available. Our supporters bonds have come through sitting by same people week in week out, going to same pubs, Chippies round ground, past memories at GP. With all this gone, and transport problems i doubt interest will still be there unless there's a change in fortunes. Add to that Everton deliberately forcing fans to get memberships, because you can't pass tickets to non members. All of this leaves a bad taste, it's just not the same Everton I fell in love with. Fans have passed season tickets to family members for years and it hasn't been an issue, it's why we kept so many supporters and younger Scouse Blues have had chance to go to game.