Flying with bikes

Am I right in thinking that if you put your bike in a bag / box, and just check it in, this is different from paying the extra for sports equipment (around £40 with Easyjet) specifically?

Flying home from France soon with bike and not too sure the best way to go about it... won't be doing it too regularly either so don't want to shell out loads on a bag / box.
Easyjet consider a bike as sports equipment so you have to pay the surcharge I'm afraid.

Most bike shops are more than happy to give away cardboard boxes and you can pack one of those out well enough to prevent a bike from getting damaged. That's probably the cheapest option for you.