here is the chart from spg showing price to miles correspondence

Price Starpoints

up to $150 10,000
$150-$215 15,000
$215-$280 20,000
$280-$345 25,000
$345-$410 30,000
$410-$475 35,000
$475-$540 40,000
$540-$605 45,000
$605-$670 50,000
$670-$735 55,000
$735-$800 60,000
$800-$865 65,000
$865-$930 70,000
$930-$995 75,000
$995-$1060 80,000
Higher prices (examples)
$2,880-$3,140 235,000
$4,960-$5,220 395,000
$9,900-$10,160 775,000