The thing is for some people it's them assuming that their way/traditions are the normal/right way. And when someone does it differently they don't have the insight to think that this is their norm; just that they've made a mistake.
So I'm Irish (and while it's customary to be generous I've never heard about this ÂŁ150 thing) so I think having Full day and evening guest is totally normal.
DP is Indian so thinks inviting everyone you've ever met, everyone one each of the parents have ever met and random invitees passing the invite on is normal.
Work mate got married recently; her family tradition is to have small family only weddings; and have a meal out with friends etc after the honeymoon to celebrate is normal; and B&G pay for the meal.
Attended a wedding recently as an evening guest (19:00-01:00) no food provided at all; nor anywhere to buy food. Evening only invite, fine. But no food; not even a soggy cheese sandwich, that struck me as odd; 6 hours, booze and no food. . .
But I'd say half the room thought this was normal; half were ready to eat their own arm. Luckily I knew there was no food being provided and DP & I had had a big dinner before hand. (I had joked before hand about loading the car with food and making a profit; a bit sorry I didn't)
Following a particular incident I've learnt not to assume; and politely ask; sometimes mistakes happen; sometimes not.
Incident was I got an invite from a work friend of DP's; only me not DP 
DP spoke to work mate (I'd never even met the guy) turned out that one of the bride's sisters was writing out the invites. DP & I both have unisex names; she's assumed that I was the male
and then got distracted and forgot to write +1
B & G to be were pulling their hair out; she'd buggered up about half the invites 
And of course there is also the fact that some people are entitled prats