How did everyone get concert tickets?

Hi guys! I'm not much of a concert go-er, specifically cause I live in a state where we dont have a stadium/pop girlies dont typically come here. so I dont really understand how ticket sales work , specifically for artists in such high demand. I was curious how some people got tickets for $100-$200 and other people got theirs for $400-$600 within the same seating area? was it a pre-sale thing? and will prices eventually go down? I really would love to see her live but i also cant justify spending $500 for a ticket (potentially 2) and also having to pay for travel (closest being oakland, ca), so just curious, thanks (: