What's your thought on people who "flip" bikes. (Resell)

I got kinda pissed when I seen the bike I was gonna buy being resold for 800 dollars more after 2 months of being sold. In my eyes I see trying to make money but having 8 bikes and simply buying a bike cause yk it's "worth 2k all day" is being a pos. Ik first come first serve but I would have bout the bike and ridden it to death. So yea im a little but hurt :/