"When it comes to" marks a topic. It is used here to warn readers that the topic is changing. It's a small change, but "when it comes to" makes it easier to understand. "As for" can be used the same way. "Speaking of which" or "Speaking of that" are good ways to make slightly bigger topic changes. "John sure is a good cook. When it comes to barbecuing, he's the best. As for me, I'm terrible with food. Speaking of which, do you know if John will be teaching that cooking class again this summer? I'd really love to take it."

Annabelle is right. Another meaning of 'it comes to' which is similar is meaning 'the total is'. 'How much is this bicycle?' 'It comes to $123.45 with tax.' so there is a kind of summarizing going on. This isn't the literal meaning in your text, but I think it is related in that the topic is being turned to another summary. 'When it comes to' suggests that what we're talking about is different from what was described before. In your text, doing good work is different from finding it. You could get paid well but finding the work might be difficult.