There are only two real issues here: How to pull it off technically, and How much to charge for it. Price is the thing that's going to kill this deal, so we m

There are only two real issues here: How to pull it off technically, and How much to charge for it. Price is the thing that's going to kill this deal, so we may as well tackle it first. It will cost your customer ~1,000X the monthly price to get this done. That's 5 figures, minimum, and it should be toward that high side of that range. And we're done. 90% of the time, a ballpark estimate will realign the customer's idea of off-the-shelf vs. custom software, and you'll either never hear from them again or they'll decide that you know what? It turns out we can actually run off your servers after all. But what about the guy who you couldn't scare away with your $34,000 delivery fee and bump to the $600/month Enterprise Plan (billed annually up front)? Well, now you have 6 weeks after the check clears to figure out how to deliver. I've done this with both of my SaaS products, and the process is the same. Take the current version of the app and start lopping things off. All the marketing, pricing, billing, etc. goes. Database gets built from schema and lookup tables populated. Kill the customer registration (after using it to create customer #1 for them), but leave the Team stuff in place so that they can add their own logins. Replace the landing page with a redirect to the login screen. Smoke test it a bit then burn it onto the customer's VM of choice. If they want to purchase updates with new features, make it expensive enough that you can do this whole process again every 6 months. Personally, I've always sold "maintenance only" contracts that guarantee timely fixes for stuff you broke in the last paragraph, with functionality frozen as of the date of purchase. But yeah, it's actually quite fun doing the implementation of one of these. And a lot less work than you'd expect. Again, though, it's unlikely you'll ever get the chance to do it for the two customers who are interested today because if you price it correctly, you'll scare them away. Here's looking forward to the one who ends up pulling the trigger!