Perhaps Florida is more expensive than you might think because the cost of air-conditioning is expensive. And while lots can go without it, as a non-native, you might find the heat unbearable. I'm using this as an example of why it's difficult to estimate the true costs of living somewhere until you've put down roots there.
Furthermore, when you're on 100k a year and saving $10k, spending $400 on a new phone is a negligible expense. If you're on $30k, and saving $6k it is a bigger proportion of your savings. If you plan on moving, you're going to readjust your standard of living and your creature comforts.
Obviously your strategy can and does work, but counting on a move working out and being able to reduce living costs is a riskier strategy (with a potentially bigger payout), and it comes with its own costs.
Many do that within the US with cost of living games. Work in SF for 5 years saving 200k a year. Move to Flordia and be set living in 40k a year for life. (Or some variation thereof)