I'm wanting to set up a small online store, and want to accept credit
card payments. Each product I'll be selling will be unique, so once
one is sold, that product will no longer be available. I am wanting to
find out whether there are any free (or if not free then cheap)
shopping cart programs that can be integrated with paypal (or another
payment system that has no fixed setup/monthly charges). I want to be
able to control inventory, ie. when a product is sold, the system will
know it's not available for someone else to buy. I have a knowledge of
HTML/CSS and small amount of javascript.

Thanks,

Nakmeister

i think an open source free php package called oscommerce would suit
your needs well. it intergrates with paypal and you can set the stock
to 1 via the admin panel for a unique item. hope this helps :) find it
at http://oscommerce.org or search http://www.sourceforge.com

Dont go through alllll that trouble,

Sell your items via Amazon.com - the most effective way to sell
multiples of unique items - and have total control of inventory
without much hassle..

I have sold 600 items so far ;)

OsCommerece or Ebay could be good options for this.

I think  nakmeister-ga is moving from eBay, in protest at the increase in fees

Try this automated site builder .. it is based in oscommerce 
http://www.jsiwebtools.com/