When a customer buys large quantities of a product, frequently the seller will offer a volume discount. For instance, one unit might cost 10 dollars, but might be offered in packages of 5 for 45 dollars. In such a case, it always makes sense buy the bulk lots to save money. In some other cases, however, it might not always make sense. Suppose a single unit were on sale for 8 dollars. In such a case, purchasing single units would be less expensive than purchasing a 5-pack.
You are given a String priceList describing the number of units available in each bundle, and the cost of the bundle. Each element is of the form "units cost" (quotes added for clarity). You are also given an int quantity, the number of units you wish to purchase.
Return an int indicating the best possible cost to purchase at least the desired quantity of units.