Here's another success story that might be interesting. This chap does invest in professional covers, but he also goes to places to do talks and presentations pretty much every week, all year. And they pay him to do the talk, not the other way around. If your friend can work out a way to get paid for this, rather than relying purely on Amazon sales, which can be notoriously dreadful, that could work. Here's Dave's story. https://medium.com/p/1129882dd6de