This becomes the point where people should be thinking about working projects on a time / materials basis. For the product that we still can make money on, great. For the rest charge what it sells for and charge for your time to order / pick up etc.
I am sure many people here have been stuck on a project doing things that may or may not have been a part of the project, but the client is dangling the final payment above your head.
This stops when the client understands that every time he see's you in his house the meter is running and he is paying.
Not sure of any builders out there that sell their custom build for a fixed price and that is what it costs in the end. Why should we? For years we have been pushed to sell a package, client expects a quote with everything included, so they can cut you a cheque for a deposit, a progress payment and a final payment. And it all has to add up to what you quoted. Plus it all has to work to their satisfaction before that last payment hits your hands.
Anyone work on a decent sized home that didn't have some sort of hiccup that cost you many extra hours that never got billed? What about the fact that we all seem to have been beta testers for many manufactures and all the hours you spend "figuring crap out" because some piece of equipment doesn't perform the way we were told it should. Pretty hard to get the client to pay for that, when you recommended everything. Now the client can say they want this or that and you can recommend things to add to the system, and get paid for all the time it really takes. Heck you can spend an hour just getting a client logged onto their services on a smart TV or Apple TV. Even better, you get paid while you wait for them to figure out what their passwords were. Don't forget, as things get cheaper from a control side of the system, that just leaves more money on the table to sell better speakers and amplifiers. They rarely have issues or cause multiple trips to site to figure out. With the resurgence of Turntables, start asking which room will be the audio room? Put together a nice higher end audio system for $10,000 or more. It takes next to no time to set up $10k worth of audio compared to a $10k control system and all it's programming.