Is buying domain names, and selling it after or have people bid for it, a good business? What are the pros and cons?
If you have a good "sniff" and intuition , you can make more money than you expect. But, buying domains, will mean to lock some money for a period. If you want to sell, you dont need to sell in the same day. You need to wait the opportunity ! And most of business ending in this way: buy a domain with 7$ and sell with 50-100$ (an useful domain)
Currently the best opportunities for one entering into this business is buying existing names for $50-200 and reselling for a multiple of that. As well cctlds hold considerable opportunity if you have the patience - example .IN if/when India becomes the superpower of this century. I would not recommend hand regging until you really get a handle on this business. Good Luck