You must calculate the virtual cost of an item based on the real cost of the item to the rounded $token.
price = 19.99, token = 5 the token cost should output 20, Tokens can never cost 0 unless token cost and price is 0.
calcTokenCost(19.99, 5) = 20
calcTokenCost(17.30, 5) = 15
calcTokenCost(0.01, 5) = 5
calcTokenCost(0, 5) = 5
calcTokenCost(0, 0) = 0
function calcTokenCost($price, $token) {
}