Definately concur with all the advice on going for quality over quantity.
Regardless of how much the quantity approach costs, the administration time is a killer.
I got caught up in the possibilities some time ago, and too many names later (in the '000s) have an absolute nightmare on my hands, from an admin point of view.
Have quickly converted to quality and am much happier for it. Good luck in your pursuits.
I personally think there are many opportunities in niche markets, with an occassional gem coming along in the two word category. I been able to find about 50 single generic dictionary words in the past 4 months, that had not been previously registered. Of course there are only a handful of .coms in that group, but I figure holding them for a few years will see some appreciation.
One thing I will say, is that dnforum is probably one of the best forums I have found for quality advice from people who do this successfully day in/day out.
You will do well to listen to the guys that have been around a while........ and to the robust discussions - they will save you many hours and potentially thousands of dollars in learning money!