I have one of the old school double edge razors and it works well-- if I don't let things get too out of control. I find it isn't always the best if I go for 3-5 days without shaving, then try to use it. The hair gets loo long and it won't get them all in the first pass. Otherwise, I've completely switched over to disposable straight blade razors (only the blade is disposable) for my bald noggin' and face. It works well, but there was a learning curve. For the first few weeks, it looked like I pissed off an army of tiny ninjas-- especially on the left side (until that hand figured out what it was doing). Now I can shave my head and face in one go and probably have a single nick 50% of the time. Besides the low cost, the nice thing is that I can take off a full 6-month beard in one pass. It's a single blade, there's nothing to clog.
As far as costs, a $30 blade supply lasts me a couple of years, and that's changing blades every week or so. On top of that, blades are available about everywhere if you travel to any far out places (that's how I got started-- got stuck in the Sahara for a few months and the only little store carried only straight razor blades).
Licensed Professional Engineer,
Unlicensed Semi Professional Tinkerer