I don't know what type camera you want to purchase, but if your looking for something cheap "under $300" then it's more likely going to be a quick shoot digital camera. Then one I use is the pentax optio W30. I use this camera for the water proof feature, but the macro feature isn't bad. The only draw back is the focus in the macro mode. It doesn't auto focus quickly, and sometimes it brackets in the wrong viewing area. This is not a problem with still images, but it's a hassle when trying to photograph insects on the move, or when you need a quick focus feature.
I have another camera, that is in the $200 dollar range, but doesn't have the water proof feature. It's Panasonic Lumix LZ3. This camera has a very good macro option, with a very quick auto focus. It's faster than the pentax.
This is a picture I took in the macro mode using the pentax optio.
It's a sulphur caught in a spider web, note the sulphur is not in the center of the focus, but instead the camera focused on the left side of the web, near the sulphur. It's one of the draw backs to the pentax optio.
The object of life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane.