You are right, I am even not sure about my budget.

Although I have the money to spend, but still want to consider all the factors: How am I gong to like the photographing experience, is there a possibility that I like it so much that I am going to be addicted to it? : ), or is it possible that I just don't have any talent in this at all that I become bored very soon.

The other thing is I use microscopy for my work everyday, and there are times when I like to shot some micscopic images of histology (from tissue slides). Although there is a digital video camera attached to the microscopy I use, but the image quality is not that good. If those SLR camera can help me to shot some of the microscopic images, that will be even better for their use.