Thanks for your reply as well! I'm not totally sure I understand so please feel free to correct me if so, but Appointments+ doesn't currently provide for the user to get custom pricing.
It's possible to create different Services to account for price variations like so:
Furniture Move - 1/4 truck
Furniture Move - Half truck
Furniture Move - 3/4 truck
Furniture Move - Full truck
Would something like that maybe work for you?
I just wanted to mention too, as an additional option, you can simplify the schedule process by having the service selection autorefresh when the users selects a service.
You'll find details on that at Appointments > Shortcodes.
Basically, there's an "autorefresh" feature you can use with your app_services shortcode. For example, you could use this:
Then the scheduling form would auto-update when users select a service, no extra button press needed.
I hope that helps. Looking forward to your reply. :)