I don't have liability insurance on my domains, but I'd guess you're looking for small business insurance that includes liability. Do you really want to go with the cheapest option out there if you are getting insurance on domains? Must be a pretty valuable portfolio, so maybe it's better to go with a company that has reputation (and maybe even brick and mortar store locations) behind them as opposed to cost. Gieco, Progressive and pretty much every other big insurance company offers small business insurance with liability. Pricing I'm going to guess will range between like $25-$50/month for any of them. But once again, it probably depends on the assets you're insuring..etc. Do a Google search for small business insurance with liability and you could probably start getting quotes online right away. Hope this helps!