Drop-shipping is a still-born idea. 99.9% of the time you will not make money, and will spend time advertising someone else's product.

Same with "buy from the manufacturer" - unless you have a lot of storage space, and enough money to hold a lot of inventory, you can't even get into that business. That's assuming the product can even be stored for long periods of time without depreciating (pretty much all of electronics is out of the question then).

Many of Flippa businesses have fake numbers, be very careful. They buy traffic to get Analytics, and when they get a few months of it, they post it on Flippa.