Yes, but you don't typically replace the same domain with two totally different services. You create 2 new domains. I would never pay someone for a service when they've repeatedly shown that they're willing to throw out the system people have started depending on and replace it with something radically different. Not only can I not trust the stuff to stay around, I can't trust the developer to have enough of an attention span to care about the old stuff enough to even just leave it alone to keep working in maintenance mode.