In Cell I10 paste the following formula
=CHOOSE(IF(E10<=$J$3,1,IF(E10<=$J$4,2,IF(E10<=$J$5,3,IF(E10<=$J$6,4,IF(E10<=$J$7,5,6))))),E10*$K$3,(E10-$J$3)*$K$4+5000,(E10-$J$4)*$K$5+12500,(E10-$J$5)*$K$6+32500,(E10-$J$6)*$K$7+62500,(E10-$J$7)*$K$8+97500)

Copy the formula down

<click on below 'star' if this helps>