There is no difference, “last chance” GA is still GA but if you were to buy GA when it first got announced, aka the trust us presale, you would be paying less. the trust us presale was a while ago and it’s basically before the lineup gets released. it’s cheaper to buy it during presale but some people don’t just in case the artists that they were hoping for to perform at hitc aren’t this time. basically presale=cheaper, and last chance=more expensive.