I am looking to start a canvas print gallery on ebay (I know there are tons already) but it's just a test really at this stage. I see many with the same images so I'm assuming they are getting them from a stock site. I have looked into it with one agency but they only supply thumbnail images with watermarks, yet these other ebay store have large images without watermarks. Does anyone know where they source their images from? I can't imagine they buy them all as thery often have thousands available.
There are places online where you can get low cost or free stock photo's. Dreamstime.com has a free images section and pexels.com is another that offers free stock images. Those should get you started!
If you are looking for free stock photos, you can also try Pixabay.com or Unsplash.com. Both have often very high quality pictures that are free and you don't need to credit the authors (though you should read the copyright rules at each site, anyway). Especially Unsplash has some phenomenal pictures. But if you do use these free pictures and CAN credit the authors (by printing a small by-line etc., I know it's not always possible), you should do so. If you think they are good at what they do, give them the credit they deserve.
Have you thought of drop-shipping? At least in the short run, removes the need to hold stock. I'd really really recommend this - gives you so much more time to think about marketting
Awesome work - keep us updated on your progress? I think marketing would work really well via an Instagram account - any experience? It's my area of expertise and I'd be happy to advise.