"Global" Attributes

[ccarpenter]

Ok well im new to using this software, and i've searched the forums some but can't seem to find an answer. For example I want to list a few RV trailers as my products. I also want to add some extra attributes like an RV cover and add the price if the customer chooses a cover for the trailer. There are only 4 different covers to choose from for any of the RV's that I list, but I don't want to force to show all attributes for every product. Like one trailer may have 3 of the covers to choose from while another may just have 1 cover that will fit it. For instance if I have 50 RV's listed and the price of one of the optional covers changes I want to be able to change the price of the cover without going through 50 listings to correct the price of an attribute. Is there a module or something to attach a price to an attribute when you create it, or something that I can change in a master attributes list or "global" to affect all listings with this attribute. I saw you can use the product combinations generator to easily add all attributes that apply to that product you are adding, but you have to manually add the price for each product. This will not be practical for me because my attributes are the same for all products, and I can't edit every single product if the price of an attribute changes. Thank you for your help it is greatly appreciated.