Dude, a fifth park should not be a priority with the current state of the parks. You first have to assume half of that budget is simply going to operating the parks, maintenance, etc and a portion is almost definitely for DVC. So if we're lucky, we get about $8.5B in actual expansion. The current parks need that and more (hell, you could spend it all on DHS and DAK and still need more money) before you even consider something so far down the line like a fifth gate.