personally in respect to Panda I would be more worried about the non informative pages than the informative pages! IE your product/buying pages are probably why Panda does not like you not the articles that have good content. I know you can't get rid of these pages as you are an eCommerce site, however I don't know why you are jumping to deleting pages. Anyone who knows anything about Panda should be telling you to add more GOOOOOOD content! not take away the good content you have. When ever a client asks me these sorts of questions post panda, I have kind of a standard answer. Do what SEOmoz do. Stick with me. You could do worse than follow SEOmoz.
What they do is have a sales area! (not everyone buys from them the first time they arrive on the site, but eventually a goodly number of returning people buy, They are very successful at selling their stuff)
ok that "Sales Area" is the S#%T content and they know it. So what do they do? They offset it with a blog/fresh content areas. I say areas because they have 2!
the first is "The YouMoz Blog" which has guest posts and posts from non-experts. technically Rand has realized that this content is just kind of filler and although Google likes it better than the "Sales pages" it is still not the content that pushes the site over the top!
So the second blog area is "The Daily SEO Blog" Which has a more expert/authority area. This part of the site offsets the "bad content/sales pages" and adds to the Google love being generated by the "The YouMoz Blog" area.
So I believe the answer to your problems is not less "Quality" content and heaven forbid removing the "Good" content you already have but adding more better/fresh/authoritative content. Even if you feel it is not converting for you. Becoming the authority in your niche is what you should be trying to achieve! become that authority and sales will follow. You are obviously not Amazon.com or bestbuy.com. So I don't think you are going to get back to page 1 by being a sales only site!
You can do a lot worse than following one of the most successful SEO sites on the web.