A party is an event you host. Hosting means you provide some hospitality.
Hospitality doesn’t have to be expensive, but it needs to exist. That means a location and some kind of food/drink which is determined by time of day. It could be platters of Iceland party food. No prob. It doesn’t have to be expensive…but it needs to exist.
If nothing is to be provided, it isn’t a party and there isn’t a host. Someone might ask friends to come for a drink in the pub or a meal….lots of groups do that and everyone pays for themselves. It’s not a party.
A party can be in your house and can involve home made sandwiches and buffet food and a table of drinks which are a mixture of those provided by the host and some that guests bring with them. The host has provided a venue and some food.
If you receive nothing in a pub room, you’ve been invited to the pub and not a party.
If you want large numbers, it’s likely to cost more. If you want 100 people, even having a few sausage rolls and sandwiches and a birthday cake that will feed everyone will cost more than it does to provide the same for 20. If you can’t afford to provide that stuff for 100, simply invite 20. At the end of the day, budget does impact hosting in terms of numbers and what can be offered.
It doesn’t mean those with less money can’t have a party. It does mean those who aren’t willing to spend anything can’t have a party…ie host an event and provide some refreshments. Someone who isn’t willing or able to spend anything on this, can invite friends to join them at the pub or for a meal where everyone pays for themselves….but it’s not a party.