So to summarize

1. You don't have anything better as a term

2. It's a valid and well understood term on the board you're on

3. It's a legitimate problem for those with finite resources

That leads to the conclusion that you probably don't pay for things often which is why you got your feelings hurt. There is literally no way that term should be offensive to you unless you abusively take advantage of services and then some then when it comes time to pay.