How to set pack and case prices?

[stratboy]

Hi. My client sends only stocks. For each product, he has 2 prices: 'pack' for 50 pieces, 'case' for 500 pieces.

In the frontend, I should display both for each product, with 2 quantity fields, one for each type. For example:

Product X

pack 50 (40$): [qty field]case 500 (100$): [qty field]

how can I do it?

I'm a php and js programmer, you can speak tech if you need to.