I would love to get away under $1,000 but could go to $1,500. And I agree - once I drive up in the car, I know the price goes up.
I'd start off with a proper factory integration digital sound processor like a JBL ms-8, Helix DSP or arc audio ps8 or rockford 360.3 or audison bit one. Especially if you are keeping the factory head unit. This makes the biggest difference in sound quality.
Or if you are okay with 55 watts rms per speaker here is a DSP that has a built in amplifier like this one which has 55 watts x 8 channels meaning you can have midbass, midrange, tweeter and rear channel all powered by this.
Match PP82DSP Digital signal processor with built-in 8-channel amplifier at Crutchfield.com
Afterwards just buy quality drivers from
parts express website or madisound website. If the shops are legit, they will know what a DSP is and how to tune one along with doing a good install. I'd recommend doing a full scanspeak discovery setup with 1" soft dome tweeter and 4 inch mids and 6.5 inch midbass for the fronts and keep the rear speakers stock but just amplified(you'll be surprised what stock speakers can do with more power on to them along with proper tuning.)
Those shops you went to "might" be good however you should be a little bit more informed when approaching them rather than walking in like an average joe that wants something nice sounding. They will give you a better deal and most likely do a much better job on the overall install if you tell them what you want. They will know they can't bullsh*t you into a half @ssed setup.
If you want a 3 way front stage setup (midbass in the doors to handle drum kicks and lower vocals, midrange in the A pillar to handle the vocals and tweeters in the sail panels or A pillars next to the midranges to handle the highs.)
Stuff should be properly actively crossed over with the DSP then EQ tuned with a Real Time Analyzer (RTA) and time aligned for magnificent sound stage rather than just the typical "take out old speakers, slap new speakers and turn it up telling you its done. That is whats called a shoddy sh*tty install."
If they dont offer any of that besides the basic install, Walk Away.
Acoustics wise, they also need to recreate a factory seal and turn the doors into proper speaker enclosures. Here are two videos detailing a good speaker install.
For a nice sound quality shop that does amazing work with very very great sounding systems and specializes in Sound quality and luxury cars, I'd recommend Reus systems located in Orange, about an hour away from Los Angeles here's the site
http://www.reusaudio.com/ I've heard quite a few of their cars and i've been thoroughly impressed with each of them. They test your car's acoustics and choose speakers that matches your car's accoustics rather than trying to make your car match your speaker's acoustics. Very knowledgeable guys.