I’d be either very broke or have to be very rich to have paid for all of those haha. Fortunately, I worked for a company that had a very generous training allotment. I’ve also managed to take quite a few entirely free by being part of their vTA (virtual TA) community, whereby I help instructors throughout the week of the course with student questions, lab setup, etc…

I can’t go into too much detail on vulns specifically but I’ve found a number of high impact vulns in public-facing websites for companies I have worked for as well as one vuln in a popular proxy appliance that I should have submitted a CVE for but never did at the time.