This morning, I stumbled across this blog post, describing "Good Consultants vs. Bad Consultants". Although it's a little rough around the edges, the points it makes are important.
The main takeaway point is the first sentence:
Bad consultants make money off their customers, good consultants make money for their customers.
When you're looking for a technology consultant to help your nonprofit organization or business, find one that's passionate about helping it succeed and sticking with it long-term! You are not solely a source of income.