Funny you should bring that up. I was just thinking the same thing, only concerning marketing. I used to work at the wal mart TLE and before quaker state came out with their new design, it didn't sell that great. However, after it got that new "Q" on there, we couldn't keep it in stock. I don't think the 10.50 has a lot to do with it as much as the new label as it was the same price before and after.
You gotta love marketing.