If function with quantities (range) [in french fonction SI]

Hi,

I need to Calculate prices depending on quantities with variable prices depending on quantity input.

Cell C218 is the quanty that the user needs to fill

Cell G218 is the price that needs to be calculated (the If function) depending on what the user inputs on C218

if C218 is empty then G218 should show 0

If C218 is between 1-4 then G218 should equal C218 * S217 [S217 contains a figure ie $1000)

if C218 is between 5-9 then G218 should equal C218 * S218 [S218 would be $800 for instance)

if C218 is between 10-15 then G218 should equal C218 * S219 [S219 would be $700 for instance)

if C218 is 50 or more then G218 should equal C218 * S220 [S220 = $500 for instance)

You get the idea

Thank