"50 more and double the costs" is exponential; in particular, it's cost(height) = reference_cost × 2^((height-reference_height)/50), or simply cost(heigh

"50 more and double the costs" is exponential; in particular, it's cost(height) = reference_cost × 2^((height-reference_height)/50), or simply cost(height) = k × 1.01395948^height.