The initial buy in for any sport is usually costly especially if it involves anything with wheels. To begin building bikes a welder is pretty much essential, I have a MIG welder that can use gas or flux core wire. It runs on household current and is fine for the thin steel used in Brads plans. Then you need a drill, a hacksaw, a small say 5" handheld grinder, one at least but 2 is better. Good gloves, eye protection and hearing protection. In my case I already had these items plus lots more because I do like to build things. But the items I listed would in Canada where I live run you around $700. Then you buy the steel, find yourself some old steel donor bikes. I prefer to add an electric assist to all my projects partially because I tend to overbuild (that means heavy). My latest build is a 2 wd delta trike capable of some storage space. The only delta that comes to mind that is similar is a Hase made in Germany. To buy one here would set me back over $10,000. Mine with some new parts plus a new Bafang geared hub motor but otherwise using recycled parts from previous projects cost me under $1000. It's not pretty and I'm not including the 48V battery since I already had it and swap the battery between different bikes.