OOOOH dear god pay the man! Dont give him your watch... a total amount for all the crap that he wants to sell you would be maybe.... 900 to 1000 for the headunit, speakers probably 200, the amps 300 to 400 then the subs at a whole 100... the install might be worth it if he wants to run fiberglass... a good fiberglass enclosure can run anywhere from 1000 to 5000. The selection that he made with all kenwood, in my opinion is because its all crap. the amps are alright... the headunit isnt too bad but the look of them are all horrid. The subs you can get a pair for like 100. If you want some personal opinions dont buy kenwood... i have seen many amps get messed up really easy. The kenwood products dont have a whole load of features or quality that a lot of other manufacturers offer.
Deck/ Headunit- Alpine, Pioneer, Eclipse... if you want a flip out get a Pioneer or Eclipse... read about some screens dying out from Alpine
Speakers- Diamond Audio all the damn way! i have two sets and the will scream your ears off ahahha and have perfect clarity too.
Subs- Diamond Audio, Phoenix Gold (high end), Alpine (type-r's), Eclipse, Infinity, JL Audio... just a few
Amps- Phoenix Gold, Alpine, Eclipse, JL Audio, Precision Power Inc. (PPI), Memphis
If you dont want to take my word for my opinions its totally cool, i used to work for a car audio shop... and we like everyone else had our money items... kenwood was one of them. its marked up pretty good... so he probably wasnt going to take much of a hit on product and a fiberglass enclosures components to build with only range up to 300 bucks. i am actually going to build my own... i have spend 200 on my materials and i got a few quotes that were well over 1000. good luck and if you need anymore advise or anything post it! hahhaha Seth