<human>: Condense the text into a few key points

So I have an online business where I sell lots of items. I pay good money on photography for all of my products. There's some sellers that sell the same items on Amazon & Ebay that steal all of my photos. I could watermark them but that ruins the whole photo and makes my brand less professional. 

I know Amazon & Ebay have Copyright forms and I tried doing it once but it ended up giving the seller all of my info in the form I'm pretty sure and then I suspiciously got phishing emails for the next month.

I'd ideally like to hire a lawyer to write a cease & desist on my behalf and send it to all of the online sellers that are stealing my photos. There's probably around 15-20 people doing this and they're based all around the world. 

Would hiring a lawyer to do this be a good idea and would it cost me a fortune? Thanks!
<bot>: Sellers on Ebay, Amazon, etc. are stealing my photos and using them to sell the same products. Can a lawyer help me make people stop doing this?