Sunk cost is definitely a factor. And how you mention getting your feet wet and then upgrading later… that’s my learning process. Back in the day mom & dad wouldn’t buy me any games so I went to the library and got a programming book with a bunch of examples. I typed the code in and then started tinkering with different parts to see what the result was with how the program ran. I do the same with computers and anything else really… get something that works and then start changing things to see the resulting changes.
I don’t see it any different with this. Start with an AIO and then necessity show that I need something so I have to learn and modify the system to accomplish my needs and goals. Or at least that’s the plan.. we all know about plans and first contact with the enemy