I want ot buy this game used today, but my question is do a lot of people still play this online, if anyone knows?
Well when you consider signing in during the day (At past midnight only 20 rooms are open) you have about 60 rooms open with people usually doing Cops and Robbers along with the freeburn challenges then yes we have a lot of people playing online. By the way you can get this game new for $20 so not a real big price difference. Also refer to the guide AOS- made so you don't get disrespected in the community. It's both funny yet educational.
I doubt that this game will lose any players any time soon. On-line play is still really strong. But please, read this guide and get to know the city and cars before you start doing challenges. Other than that, I have two words for you:
You wont regret it.
One more question..Do u have to buy all those cars and the cops and robbers game? Does anything come with the game?
You can earn all original 75 cars yourself and all those packs on the PlayStation Store are optional. Though if you have the disc version you're in luck because there are these sponsor cars that you can get after you reach a certain license (Note you have to do stuff to get them after the update. You can ask about that when you get that far.).