I would have to work it out for the entire system as I already have some of the kit from a previous install and I am having a Clifford alarm fitted at the same time.
I can tell you the most expensive part of the system is the main amp. I wanted to keep the standard headunit so not to ruin the look of the dash. In doing so i needed an amp with a on board processor to split the frequency’s between the door speakers and the sub amp.