BHW used to have a lot of threads about "if you had $500 to invest, what would you do with it?" so I'm going to try to address all of those questions. This is going to be a short post, but basically I'd hire an experienced expert in your field of interest by booking a 15-20 minute call with them. Consulting directory: https://clarity.fm For example, Nick, founder of one of the top 10 ranking blogs for "seo blogs" on Google knows his way around SEO. He costs $5 per minute. 20 minutes, that's $100 and he'd answer every question you've ever had about your SEO uncertainty. Thomas Smale also has a profile there among other experts. Instead of putting $100 towards a couple micro niche sites in the BST section, spend some money on educating yourself first. There's a lot of garbage info out there, and it's hard to trust. Call an expert in their field, and ask them your questions. I think a lot of people don't invest in themselves as much as they should.