I hope you have better luck than I did!<p>A few years ago, my partner and I built vendazzo.com (now defunct). It was an e-commerce search engine on products listed on Shopify shops (sound familiar? :)). At the time, we had > 100m products listed, and I don't remember how many shops we were indexing.. over 100k I think, but we had access to over a million. Overall, I think your approach is very similar to ours, but we managed to keep our costs lower. At the time, we were spending ~$550/mo, and our search times were under 300ms. We had established partnerships with a number of shops, and we had a few users, but not nearly enough. That's where the wheels came off. The site operated for over a year, but the monthly costs wore us down until we finally decided to pull the plug.<p>I still maintain that this is a good idea, and constantly have to fight off the urge to "try again", however, to do it properly, I think funding would be necessary, or finding some way to organically gain a lot of users.<p>Looking back, there are things I could have done to reduce my opex further, but in the end, it still wouldn't have mattered if I couldn't figure out how to acquire users.