My dd was asked to a 5th birthday party recently at a softplay centre.
Turns out there were only 5 of them that were asked so not a big enough group to have an official party arranged at the centre. The Mum provided cake and snacks, and we all brought a gift, on arrival we were asked to go to the desk and pay for entry.
I didn't mind paying, but I think if it were me I would have just payed for the group if I had invited children to come.
I would be interested to know what others think?