Ya, some employers simply don't understand this. The last two times I've moved, the total costs were upwards of $50k, and that doesn't include the $50k I lost on the first house (due to the 2008 financial crisis).

My last boss offered me a $30k/yr raise to move to a different country for a small promotion with no real path forward beyond that. I said, "no way... it would take 6 years (after income taxes) for me to pay for that move with the increase in salary, and the new country's higher income taxes."