The camera is enough to do what you want. The 18-55 is an alright (read: kit) lens and would be slightly better if it was the VR version. You will need a macro lens to take the good macro shots or get really creative with filters, extension tubes, teleconverters and the like.
The macro lenses run in the 500-1000 ball park though so once you have the camera you're at best 1/2 way there.
Make sure the 4yr warranty can be transferred, a lot of times they can't. 3g is a funny size for a card (usually 2, 4, 8...) unless it is 3 @ 1gb.
As for if it is a good deal or not, compare it to what they are new. The lens isn't worth a ton used and the tripod may or may not be a good one; without a brand it is hard to tell. You'll have to make the call there. Shop around to be sure.
