i don't understand the "slots are cheap" vs "slots are expensive" over time debate as slots run a math model with a reported RTP. Due to the increased volatility of modern slots, many more people are being unlucky (and more people are being VERY lucky) as the volatility would suggest. So it's totally possible you are just consistently being unlucky..
Although i do agree that the large format bonus buys are ridiculous for 99.9% of people (due to the bet size issue), it is just an inflated bet size running a math model similar to a base game spin (for example). I'm not sure if that's greed or who knows, but i do agree it feels weird to put that much money down for such little action..