small php admin system

I need a very simple easy to use small application that will admin to login and change prices throuhgout a small site on various pages rather than having to edit every page each time a price change occurs. It will need to allow single prices plus combination of products. For eaxmple there will be product 1 price, product 2 price, product 3 price - then a combination price for product 1 + product 2. It needs to be simple enough if possible for me to add products in the future and copy the code to the relevant pages if possible. Im not looking for a full cms system. Hope this can be done. This needs to be done quickly if possible as my usual programmer is away on holiday.