Well, it can be cheaper, then again it can also be more expensive as well. It all depends on how far you want to take the acquisition of fancy tools, and high end components. I'll say that if you're willing to look around and find some closeout deals, you can build a killer rod for under $50.00. Now, it may not be the lightest, crispest most technically advanced rod, but providing you take your time to understand proper setup, and are willing to spend a little while attending to the details, it will still be better than anything you could buy off the rack. I would suggest you get a copy of Rodbuilding Guide by Tom Kirkman to familiarize yourself with the learning curve, and to make sure you understand what you're getting into.
Building rods isn't for everyone, but I can guarantee you that if you enjoy the satisfaction of tinkering with your equipment and tweakin it to get max performance, and you enjoy devolopig your skills as a craftsman, you you'll really enjoiy it a lot.
Let me know if I can help.
Best Regards,
Andy Dear
Lamar Fishing Products