Quantity Dicounts

I would like to offer discounts to customers for purchasing over a certain quantity of a specific product (otherwise known as bulk discounts). When creating discounts, there isn't that option. I thought I could create a new product from an existing one and label it a "10 pack" to offer different pricing. However, I am running into inventory tracking issues. For example, if I have 50 wallets posted as one product and then subsequently posted the 10-pack of the same wallets but label it as 5 available, then the inventory does not track across the product. Someone could essentially by 5 (10-packs) and also 1 single wallet even though I only have 50 in my inventory. Is there any other way that I can offer bulk discounts while maintaining my inventory integrity?