Agreed, I think by posting on CS we are self identifying as people who like modding cars:)
I just found myself in a situation where I had spent money and was considering spending more money on my car that I was going to be replacing soon that I wouldn't get back when I sold it, so decided to put that money towards the new car. i.e. further mods on my current car would delay buying my new car and also mean I would have less $$ to spend on modding new car. Made me realise I should have just bought the car I wanted in the first place rather than a stop gap..
Everyone's situation is different, and springs are easily reversed and you will probably get most of your money back if you revert to stock and sell the springs. And as you say, it will be fun and he will learn a lot from the process.