Just Wondering browsing online i saw some pics of people useing nice boxes and no insert
No you don't have to use them...and if your cupcakes fit snugly in the box with little room for movement they should be fine...but inserts don't cost much and they provide a lot more security for them in transport.
I buy my cupcake boxes and inserts from www.brpboxshop.com. I buy the plain brown no frills boxes in 10 x 14 with the matching 12 cup inserts....really not a big investment for the peace of mind.
It depends how you have frosted your cupcakes. If it is all the way to the edge, then it pays to have inserts as it keeps them apart and saves damaging the frosting. If the frosting is a bit more inside the rim, then there is no danger in placing them straight into the box.