Not 100% sure, but my understanding is that you (I mean your theme code) can’t know what discounts apply until you add item to cart and only then this information is available, as not all discounts are as simple as yours.
With some hackish javascript your can do it in background and update the data displayed on the product page, but …
In your case you may be better off by simply outputting the {{ product.price | times: 0.6 | money }} (and so on) based on some condition?