Make ordering a product dependant on another product

[fdangelo]

Morning bus ride is $850/year.
Afternoon bus ride is also $850.
Buy a morning seat at $850 and add an afternoon seat for $350.

If I use the Related Products method, someone (who doesn't actually want a morning seat) can go to the morning product, and click on the afternoon add-on product and purchase an afternoon seat for $350, without having to buy a morning seat.

If I use the product option method, information about the afternoon product is not displayed because it isn't really a product, it's just an add-on.
Furthermore, I assume that the inventory counts for optional add-ons and actual products are not linked, so controlling capacity would be a manual operation.

My question is: How to make the purchase of a product dependant on the prior purchase of another product?
For instance, a discount for the afternoon product if you order a morning product.

[maxter]

Sounds like you need to a custom solution.

You can check this  promotion extension, but I am not sure if it looks at prior orders
http://marketplace.abantecart.com/promotions-management

[fdangelo]

I think I've found the solution.
While browsing the extensions marketplace I came across the "Product as Option" extension.

It does just what I wanted.
You attach related products and the customer can choose something.
Being able to see the original product page is optional, so they can never get into the discounted prices, since they are not accessible.
And the product as option is tied to the same inventory.

[maxter]

Oh, right. That sounds good.