I’ve built the “fair” price range based on my hourly rate and put samples in my portfolio that reflect the prices, the effort and the time spent accurately. This way, most of the time I don’t overwork myself for peanuts and the client gets exactly what was paid for in the end, no less, but definitely, absolutely no more.
The more difficult and time-consuming projects I either decline to do or charge more for. The downright inadequate requests (links to $2000+ projects on behance with a remark “we want something like this”) I also decline.
Selling for cheap to a reasonable degree to build the profile is a good strategy initially (and by initially, I mean month or two) but after that, you’ll overwork yourself into a coma eventually and create and encourage a client base that runs around terrorizing everyone and demanding the aforementioned $2000+ projects made for $5 (or $100, for the matter, because $100 is so much more expensive than $5).