Thanks for all the great answers.
My problem with this, specially in large projects is. Lets say ok I create an inheriting class for the changes on page2. But offcourse the customer now wants a change on page3 different for the one on page2. So I create another inheriting class.. Then suddenly 1 year later the customer asks me for the same change on page1 as on page2, but because i was so busy with page3 before that I forgot about the class i made for page2 and I start making another inheriting class for the changes on page1.
Like this after a while I end up with loads of classes even unnesecary ones.
How do you guys keep this all in order?