Auction Dynasty help

Hey footclan, I’m currently about to begin my first ever auction draft and it’s tough to know the values of some players in correlation to the budget. It’s a 28 man roster with 1QB, 2RB, 2WR, 1TE, 3Flex. It has a $450 budget. How much of the $450 budget would you spend on a guy like Saquon? Thanks!