The worst tool for the job

The first thing you need to make the kind of illustrations he's making are the ability to automatically route the lines in a way that doesn't look embarrassingly bad. (Not the Bezier curves that Powerpoint comes with)

The other problem is how to lay out the boxes so that the diagram tells a story and that is a matter of elbow grease and having pride in your work.

All of the time somebody shows us a hairball of 10^6 nodes that have 10^8 connections or so and expects to get praise for it. If the culprit is lucky they might make the cover of Scientific American or something, but nobody is the wiser after looking at that type of diagram.

I do have some expertise in some of the areas you mentioned, and disagree with you:

Musical instruments: if you're starting off on guitar, get a used Yamaha for $80 and spend as much money as you can on lessons. It's better to be a virtuoso with a Yamaha than to have a high-end Martin you can't play collecting dust in your attic. I have been given more than one expensive guitar because people heard me play and thought I'd get more out of the guitar than they were getting out of it.

Bikes: I got a fixed-gear bike for $90 to use as a daily commuter. A month in, I was tired of getting flats, so I replaced the tires with Continental Gatorskins which cost more than the bike originally did. After that, the bike lasted me >5 years without modification, only occasional tune-ups. I got rid of the bike because I was bored with it, not because there was anything wrong with it, and paid $250 for a system that was functionally the same but looked a bit nicer--the only real upgrade was a Brooks Leather saddle. Tons of bike messengers are running similar systems far harder than I am.

Both music and biking have somewhat snobby subcultures that will talk crap on cheap gear to justify their own lavish purchases, but ultimately nobody can say anything about what guitar you're playing when you bust out Paranoid Android or what bike you're riding when you zip past them. Skills beat gear every time.

Basically, combine a low-risk strategy with a high-risk-high-reward strategy and avoid medium risk. That way, if the high-risk strategy fails, you won't be completely ruined, but if the high-risk strategy succeeds, you'll have a big reward.

But are there cheaper drills that do the same?

Quality, mid range equipment. Not luxury.

(The examples are unfortunate. For a runner it might suffice with $100 worth of equipment but not for a cyclist.)