I have just recently been practicing with my el'cheapo Sigma lens that I picked up for around $20 at a local pawn shop. I actually like this lens at least until I can find a better macro set up.
These shots are hand held and I rather surprised myself when I loaded them up on my computer. I dont like how images come out on this forum when they are uploaded, they are way sharper then the original images on my computer.

[snappychappy]

I think you have some excellent results from your bargain lens, rich colored and quite sharp shots.