Charging money to attend a party?

I have some friends who host an annual Halloween party at their home.

In the last few years, they have hired a caterer, entertainment, and a bartender, and they have asked each guest to pay $10 (minimum) up front. This includes, open bar (frozen rum drinks, and beer)

I've gotten in arguments with my wife because I feel it's the utmost in bad manners to host a party and charge your friends admission.

Other parties, everyone brings a dish, and byob, but it's never a requirement. If we need a beer run, it's 'pass the hat'..etc.

We've had great parties, with live music, because many of my friends are musicians, and it's bring what you want, but please attend, and there is never a cover charge.

This couple also has very expensive Halloween decorations....spiders the size of a small car..etc, and by paying them an admission fee, I feel I'm also helping to pay for their decorations.

Of course, I've been to bashes in the Summertime, where it might be $10 dollars for live music and all the beer you want just to cover expenses, and make sure the band gets paid, but that's different in my view.

Is this an acceptable practice, or the utmost in bad manners to host a party and then charge your friends admission?