As a person who's been buying and selling sites for years and is new to the domain name game, I'd say go with domain reselling. You will make the same amount of profit with less effort. Sites are a big hassle to create, develop and to move to new servers. And most of the time, people will bid so low on your sites that you will barely just get back what you paid for it. Better yet, try a bit of both and see what works best for you.