Ebay does offer to let you look at more than 2 weeks if you pay for it and there is at least one ebay sanctioned site that lets you look at several months of data or a year or so of 'trend data' but not specific item data.
I've never really figured how popsike stays around since it appears to me that they don't have any blessing or affiliation from ebay and ebay's fine print says you can't use their data without permission. Maybe they do have permission or pay ebay but it doesn't seem like it.
Get this:
Long before I knew about popsike or anything I tried to create my own database. I had a primitive macro which would copy a page of completed auctions to a spreadsheet then click to the next page of completed auctions and do it again. If you configure your columns in ebay you could get a pretty clean layout in excel. Once this ran and copied 20 or 30 pages of auctions I would clean it up by copying it to another spreadsheet but just the data values, no formats or pics. It took about 10 minutes of work to get it sorted with all the extraneous junk gone but in the end I had thousands of completed auctions in a spreadsheet you could sort by price or artist or whatever you wanted.
I figured if I could capture a significant amount of data I could probably put it on a CD and sell it to interested record buyers or sellers - it would be pretty useful considering there was no popsike or similar sites at that time. But, it was way to much work (and I was only doing records/hip-hop completed auctions) and then I saw ebay already had it in mind to do something like this and also I found out about popsike.
