Much of it will depend on where your skills are, and what you're willing to commit to. Nothing is too complex that it can't be broken down into its component parts.
Timing and planning are primary factors, more-so than the monetary aspects are, in my opinion.
After being a designer for years, and being familiar with construction, it was a perfect fit for me. I essentially needed to aquire better sewing skills and familiarize myself with the variety of materials that are availiable to me. It's a matter of starting small and aquiring skills as proceed. I can't count all of the basic bags and sacks I've made since I've gotten into this D.I.Y. camp gear thing.
I'm constantly perfecting one item, and altering another, that's just me, it's a passion. I don't think that you should get into it if cost is primary desire. It's a personal thing of finding patience and pride in your own creations.