I have to admit that I too am looking forward to the build challenge and indeed that was part of my rational for going the ubitx route. And I have to admit the fact it is qrp is also an attraction. The PA part is because I may just get bored not making many contacts.The fact that it is open source software is also an attraction.
I have about 150 dollars invested but I can add to the radio for a little dollar amount spread over time where as 400-800 all at once is impossible since I am on S.S. (saving that amount is impossible )
All of my antennas are down and will have to be redone (hurricane Michael) but I have all the materials to do that.