wow...lot of nay sayers here. Passive income does exist in IM. I have a site that I built 2 years ago just as an example to a friend on how easy Wordpress is to build sites. I wrote a few articles. It doesn't even rank in Google. But it ranks in Bing and Yahoo! and is generating $500 per month completely passive. Really...it's passive. I do NOTHING month to month to keep that money coming in. And it has continued consistently for 2 years. It's monetized only with Adsense. I tried some Clickbank offers, CPA offers, and even Amazon affiliate ads, and nothing converted anywhere close to Adsense on this particular site. So I took it all off, spent a couple weeks testing different ad placements and formats to maximize my click thru rate early on, and let it run. I've been full time in-house and not building much of these on the side, and am only now starting to build up a second "authority niche site" w/ 500 or so articles/posts monetized w/ adsense. My costs to start that site were a $10 domain, about 6 hours total writing content and setting up my theme. I don't count hosting, since it's just on my hosting account that I use for other things, but if we must count it, it's about $60 a year I think.
OP, if you're serious, you can do it. Don't spend your $100 capital on courses though. Everything can be learned here for free. Find tutorials and "journey" threads, they're great! Learn how to do keyword research and how to select a niche. I think Bluematter has done some good ones. And the key to succeeding is NEVER give up.