If you're going to be on it long(ish) hours, you want a fair bit of power and you're going to be doing graphics / development, I would probably recommend to go with a desktop.

Like you say, the economy is going to be better and you most certainly will get more 'bang for your buck'

Plus they're great to work on! Okay, I guess with a keyboard and mouse, a desk and your own monitor, you might not tell the difference, but then it defeats having got the laptop in the first place!

One other thing. If you're custom building, chances are you're going to get better hardware longevity too. Personally, I don't like the idea of working on a cooped up laptop for 6 hours +, but my own PC would be plain sailing for days