My opinion may be unusual because I am a marketing man. I think including all the pro apps free at first would cheapen the brand for UNA, and end up leaving people feel trapped into buying upgrades when old versions hit EOL or core code becomes incompatible. They may also feel trapped into having to hire UNA to configure the pro apps if they cannot do it themselves due to lack of skill or experience.
Maybe half price instead of free helps preserve the brand but sooner or later people are going to feel like they have been trapped. Then there is the fact that an upgrade itself can break a site.
I don't mind paying for code that works. That's the real issue: UNA code just needs to work, out of the box, no questions asked. If you give away the front end for free you may end up having a lot of users who are incapable of running a site in the first place due to lack of experience. Then they will run around giving bad word of mouth.
Using UNA is not like using WordPress, which is pretty beginner friendly. It's more like rocket science or at least advanced math class. The experience reminds me of something somebody once said about choosing UNIX as an OS back in the early days of UNIX. Choosing it as an operating system was like booking an airplane flight on an carrier where you had to bring your own seat and your own tools so you could bolt it to the floor before takeoff. It's still a little bit like that without something like cPanel. lol.
Back to the brand issue: Consider Apple. Apple stuff has a reputation for being easy, and just working so that somebody doesn't have to have as many tech skills to use it as compared to android or windows. You take a new apple laptop out of the box and turn it on and it finds your network all by itself. I remember the first time I saw that happen. My jaw dropped.
I suppose the gap is closing, but look what Apple can charge for their hardware compared to what others can charge (that price and profit differential is the whole point of doing good marketing (keep in mind that product development should be an integral part of marketing). The more problems you solve before they become problems (read make things easy and idiot-proof) the more you can charge while maintaining a happy and loyal customer base at the same time. When the goal in business becomes to sell more units at any cost, instead of make something the best it can be, the battle is already lost. Lot's of discount appliance stores have gone out of business over the decades trying to lose a little money on each sale while making it up on volume... ; )