A: I was just looking at CityMax and noticed that they have their own affiliate program. Have you asked them if they have a home grown technology they are planning to roll out, or are they powered by a third party?
Anyhow, I see on the CityMax page about Shopping Cart Conversion Tracking Pixels that they mention the following:
Affiliate Conversion Tracking Code: You can use various third parties that just require that you insert code on the payment completion page.
Though you’ve requested advice on “a stand-alone product that doesn’t cost thousands of $$,” it sounds like you’ll have to go with an ASP.
The CityMax system appears to easily integrate ASP affiliate tracking, but server side tracking could be tricky.
Some tracking solutions I would recommend (combination of quality and attractive pricing) that you consider are Affiliate Clicks, FusionQuest, and ShareASale.