I use a macbook pro and it truly is a better laptop than anything else, but if you're looking at a desktop then the argument becomes a lot murkier if you're not doing iOS development. If cost is an issue, I'd build a windows desktop from parts that are OSx86 (Hackintosh) compliant so if you need the osx experience you can get it. That gives you the best of most worlds' I'd say without having to pay the mac premium - though if you're getting a laptop, then the mac premium is almost certainly worth it IMNSHO.
It's not that it's not worth it, it's more if he's constrained by price he could get a perfectly functional self-built pc for a fraction of the price of a mac.