After the OMEGATON-WTF-BBQ-3000!!!1! sale Gamestop did between Sept 2012-November 2012, they removed all of their 49¢ and 99¢ titles off the website, which, at the time, were around 1/3 of all PS2 games they had in stock. You can't find those games anymore by searching the website. But a few stragglers somehow managed to survive the website purge, and those are the ones you see listed as 2¢.
You really aren't supposed to be able to find them in any Gamestop anymore, but sometimes you get lucky and you find a couple creep into a surplus that was shipped to a higher-level store, or you can find one that slipped by the inventory counts when they were being sent back to the warehouse, or you just get lucky and find a high volume store that didn't care to go and pull them to send them back.
I had purchased over 400 discs during the sale, and while things were still "active" on their website. I managed to nab a few sealed games and mint-condition games as well. Chulip, which they were selling $1.99 used and $9.99 NEW at the time, I ordered used and got a new copy. Secret Weapons Over Normandy was another sealed one. Then other games like The Shield, I got basically an opened new copy. Everything was pristine.
I actually just got back from one Gamestop in the area that surprised me for having Gamecube games in stock (also matching the PS2 75% sale) and a somewhat better selection (barring all the copies of Madden 2003). Probably 4x the selection of titles.