I have successfully used a couple of the cgi based shopping cart systems in past releases of e-smith (sorry name escapes me right now). I rememver looking at Akopia's offerings for a few hours but it requires a little more extensive configuring and I only had 25 products to worry about.
I would do a search for cgi/perl based shopping cart systems that are not database driven. If you don't have many products this should be more than enough.
Justin