Looks like I will have to do a shitload of reading to understand how to put one of those together?

I should probably go for an easier gun for my first one but meh... The challenge will be good.

Something like this looks like exactly what I would want.

How much would the parts for this cost?

I have never made any sort of cannon before (potato or otherwise) and want to get into it to have a bit of fun.

I was hoping someone could point me in the direction of a "How to" or a few designs for a fairly decent golf ball launcher? Pneaumatic is my preference but the guide would need to be ...