I didn't steal your cat (as my logo)

Dear Rich: I am starting an e-commerce store and decided that I wanted to use a cute spotted cat as a logo. I found an artist through Google searches that had a cat that I liked without the spots (she would be in the category of "starving artist" as she sells her original works through venues like Zazzle for about $20-40 each). I contacted her and asked if she would custom design a logo for my new store and that I would pay her for the work and also for a license to use the work on the site and on T-shirts etc. She acknowledged that she received the request but then she never responded to the actual request and started to ignore my attempts to communicate with her. Since I have art ability myself, I painted a spotted cat in a very similar style for my site. I realize that this could be considered derivative art and that she could declare copyright infringement and potentially issue a C&D. From everything I have read on your site and elsewhere, due to the fact that there is really no damage to her in that she would not be suffering any real material loss, that this case is really small potatoes considering both parties material worth, and that she probably wouldn't pay a lawyer to prosecute, the risk that I would have to stop using my image or suffer any other negative consequences would likely be low. Do you agree? Also, if she were to pursue this, we would be more than willing to pay a licensing fee to use the image. If the dispute were ever to go very far, do you agree that is likely how the case would be settled (i.e., pay a licensing fee)? I work for a large pharma company so for better or worse I see this sort of thing with patents all the time - the attitude of "we work on it until someone tries to stop us and if the other company is small enough they can't keep paying the lawyer's fees, will take some money and go away, and if they are big enough then they are more likely to want a piece of the action if it is a successful drug." Thanks for your closing argument ... er, I mean question. Just so I'm clear about your situation, you asked an artist to create a work in her style and she wasn't interested, so you copied her work or style or both (we're not sure) and if she chases after you, you'll consider paying her. Hmm... we think we understand why she's a starving artist.  
The realities. But hey, the Dear Rich Staff wasn't born yesterday (unless yesterday was, like 100 years ago). We understand the realities and we respect your willingness to pay a reasonable license fee, if asked. We should mention a few things that may inform your decision. We haven't seen the two works but as we have mentioned before, when it comes to portraying elements from nature, the more that the work resembles the actual thing, the less protection it will have. 
No pain, no gain. As for your claim that the artist is not suffering any material loss ....  We hope this doesn't sound too naïve, but if someone takes your stuff and sells it on t-shirts, isn't that a material loss? (y'know, just sayin'). Reverse roles and we're sure you'll feel the pain. 
If the artist comes after you. Should the artist chase you, you do have an email trail indicating that you sought rights (which is good) but when rebuffed you went ahead without permission (not so good, as it indicates willfulness -- a negative quality when assessing damages). (A fair use defense will obviously not work for you as you are not transforming the work and you're using it for a straight-forward commercial purpose.) We can't say how you would fare in a dispute like this but we're a little dismayed that the rules of big pharma patent infringement are being applied against $20 Zazzle artists. Oh well, we'd like to stay and rant but we've got to get ready for a one o'clock presentation.