For what you want look at some refurbished and "older" cameras with lower MP.
Here is a "cheap" option cost wise but with all features you need for taking mini photos. Since this is a 5.0MP camera but you don't need more then this. More MP doesn't give better picture quality per se. ie. A 5.0 MP camera with good optics will produce a better picture then a plastic lens of a 12.0 MP camera.
http://www.overstock.com/Electronics/Samsung-s630-Black-Digital-Camera-Refurbished/3239526/product.htmlI'm looking at the following information on this product for taking Miniature pictures (Macro photography)
Macro: 5 cm to 80 cm (wide), 40 cm to 80 cm (tele)
Allows for short focal lengths (get close to subject)
ApertureF No.: F2.8 to F7.1 (wide), F4.9 to F12.4 (Tele) -
I even go higher then 7.1 but this is fine for your use.
SHUTTER# Type: mechanical and electronic shutter
# Speed(TBD): 1 to 1/1,500 sec.(Manual: 8 to 1/1,500 sec.)
Controls the time the shutter is open. As you increase the aperture number you decrease the amount of light that gets in your camera. It is necessary to have the shutter open longer to let more light in.
White balance: auto, daylight, cloudy, fluorescent, fluorescent, tungsten, custom
I'm really looking at the "custom" setting on here. Ever see mini photos that look yellow or blue? The problem is the W/B or white balance. You need to tell your camera that this is "white" light. For minis, custom W/B is best.
Essentially you hold a piece of blank white paper in front of your camera, press a button. The camera then "records" what it sees as "white". You'll get very true color representation in your photos if you do this.
Good luck.