Instead of dragging your feet for years it would've been a lot smarter to take the 30% raise with current book and make it a three year deal with a me too clause after that point to take the average of your peers if they have increased by then.

It's far better to negotiate incremental improvements then swinging for the fences which rarely ever results in a home run if history is any indicator.

It's also beyond laughable to include legacy pay in your calculations and it will be laughed at. You'll never get released with unrealistic expectations and actually you'll play right into management hands - the longer you hold out for a home run the longer they stockpile cheddar. As for not being able to staff that is also laughable as your classes are running nonstop and are full, so clearly compensation is not an issue attracting new hires.