adding multiple pricing levels in a woocommerce product

I have wooccommerce running on a site and have a product page that needs multiple pricing levels:

The main price is $499 but they also want to add the ability to add a spouse for an extra $250. How would you do this? Also they are considering splitting up the overall blanace into the following monthly payments:
$299 at the start
$100 a month til the bill is paid off.

how do you do all of this?