SunshinePHP is by far one of the most iconic PHP conferences around the globe, but more importantly, in the USA. I've attended each year since it's first.
It has been held in the warm city of Miami (since in the US, most of the country is frozen in February) for 7+ years and, regardless of when you purchase tickets, every year there are high-quality talks worth listening to.
Each year a few months prior to the conference the organizer releases "blind" pricing. During this period, you will be paying to attend a conference about PHP without knowing who will be speaking, but the price is unbeatable making it easy to justify a conference even if you have to travel.
As an example, the blind price of the general admission plus tutorials is less than the general admission alone if purchased later.
Now if want to get in for free, and still help the community, how about becoming a speaker? All you need to do is to pass the CFP selection process, which is now open.
See you there!