...buy a quarterstaff from a local martial arts supplier there would be a major difference.
Only in issues of finish. The one from the local martial arts store will be much prettier, but it tends to be able to handle only as much as abuse as a broomstick. Nowadays, they don't make them for hitting people, but for kata--so they're very light, very fast, and very, very, very fragile. In truth, if you find a thick branch with some good heartwood, you can make an excellent staff that more durable and effective than the stuff you buy at martial arts stores. It won't look cool. It may even be irregular or crooked. But it works great.
I think it's one of the traits of our modern society--being so far away from the actual construction of objects--that we ascribe superior quality to something that is machine processed.
Now, Reklaw, let me tell you something that will save a load of money on bo, hanbo, and jo. Go to
Home Depot or
Lowe's. Look in their closet supplies section. They sell red oak closet rods that word excellent for martial arts applications and cost a fraction of the stuff you find in martial arts catalogues. Give 'em a decent licking with 150 grit sandpaper, until they glide in your grip. If finish is an issue, get some linseed oil and apply a couple of coats. You can do it with a paper towel. If you want some decoration, take a butane lighter and lightly scorch the wood to make ring patterns or darkened ends or whatever you want. The scorching will strengthen the wood, too.
It's cheap. I've a couple of rods that have lasted seven years. One of them I've even fooled around and used to smash bricks.