I think he is talking about making a SAaS tool that works like SB, but on the cloud ( I hope so lol. ).So clearly you'll need to upgrade to offer anything with any subscription, but more so have you spoken to @Sweetfunny about this before making any announcement?
In that case, I think it could work. Just be sure to keep the pricing (atleast entry level pricing) reasonable.The price of the proxy would be included in the subscription ( but maybe a search limit depending on the subscription), the user won't have to do anything about the settings etc... I find that for a beginner this tool can be quite good to start using scrapers easily.
Unless he can scale it up properly. For example, distributing jobs in between servers.From programming view it's bad idea, making multithreaded web app with multi users using it ... it's good way to crash your server resources ...