Do I Need a Practice Staff to Learn?

The short answer is no.

As much as i'd like for each of you to buy tens of sticks from me, there is no absolute reason that you cannot practice and learn with a fire staff. 

My non-fire contact staffs have a couple more inches of grippy, play space than the fire staffs, but very rarely are you going to be using those inches.

The main benefits are the pretty colors and the cleanliness. Once you burn a fire staff, even if you regularly wipe down the flowers and silicone, it will be sooty. It will transfer soot to your hands, to your face, to the ceiling of your car, the walls of your house, and whatever floors you practice on. If you love spinning fire, you will probably love this to some degree, but maybe having a prop that you can play with without leaving a trail of soot behind you is a benefit. That's up to you.

The lacrosse ball ends do hold up to wear and tear better than wicks. Two of my great pleasures are using my contact staff as a walking stick on waterfall chases, and sitting on the floor and rolling my staff around me with one of its ends rolling on the floor. Both of these activities will degrade a wick, but normal practice drops should not pose a concern.

With my default builds, the weights match. Having a fire staff and a non-fire staff is also a great way to start exploring double contact staff.