Probably somebody has already suggested this as it seems fairly obvious.
A lot of people give heat/cold to a deal based on personal opinion of the item, rather than the deal. I suggest having to ratings, 1 for quality of deal, 1 for quality of item.
I do often find people's opinion on an item interesting, so I'm usually interested in both the quality of deal and quality of item. Splitting it up would give a better idea, and hopefully people would put their opinions in the right place!