Sounds like you are making some progress, do you have a circuit diagram for us to check out?
Out of interest, what transformers are you getting and where are you getting them?
Regarding price... no, this certainly isn't a cheap way of getting an amp. Some of these components are very specialised and correspondingly expensive. For me it was far more about having a project to work on... and the fact that it's easier (for me) to get project expenses past my wife than purchases. ?
Although, having a completed build that sounds great is a fantastic feeling.