I haven't had a season ticket for years due to work commitments and other things, but due to different circumstances now, I'll have only missed 3 games this season at Priestfield. I expect a similar pattern next season, so for me it's a no brainer. 20 x £24 is £480. That against £300 means I save £180.
And if we have a good season and I find myself going to all 23 games, it's a saving of £252, which works out at £13 per game, a saving of £11 on each match. Like I say, a total no brainer, I'll be getting one, as will a few others I know, based on the maths above!