upgrade radial addons for existing products?

how can i add an addon for a product that is already in my store?

Example: Lets say im selling a computer and i want to have the option to upgrade the hard drive and have different prices for the upgrade.

And have it re calculate the total and check out.

please help

This is not easy to achieve in ZC, because the current programming does not facilitate dependant attributes. (the options offered in attribute B is dependant on what the user selected for attribute A).

You could probably be creative with how you configure the attributes to achieve some representation of the radial add-ons, but with computer hardware you do face a challenge, because sometimes the selection of one radial add-on may be influenced by other radial add-on choices, eg:

You can only have Hard-drive "ABC" if you previously chose Motherboard "XYZ", as any other choice is incompatible...

Sadly, current zc can't do this.

heres my example

http://tinyurl.com/c3tqac

steveAR:

heres my example

http://tinyurl.com/c3tqac

can anyone help me do this?