Yep, no reason to go cheap when the chain is concerned.

 

Mother of GOD! I've never seen such a worn sprocket. Dude, get it changed before you ride. If you try to dump the hammer on that sprocket you may find a thick chain ripping your calf off. Be careful brother, "It'll choppa u leg off."

Yes, you HAVE to change sprockets and the chain at the same time, they wear together like feet and shoes. Find a savvy friend and have him look over your ride. Remember: a poorly maintained car leaves you on the side of the road while a poorly maintained bike leaves you skidding down the road on your head.