Not quite...and not to be rude either but Class D rules the cost per watt ratio unless you're looking at full range class D amplifiers. Typically Class A powered amplifiers are the end all. For full range, Class A/B is where the masses look and to keep costs down, Class D is utilized for anything playing below ~500mhz since the benefits of an A/B design effect mid-range moreso than mid-bass or sub frequencies. It's also because Class D is more efficient so it's easier to design and produce more power with less heat constraints and ultimately smaller products.
Almost all audio circuits and design are the same for the last 30+ years except for the recent introduction of full range class D. What you're paying for these days are quality of components, brand name, and the costs of packaing/marketing/etc before it gets to your door.
The mechanics of your install is what decides the "sound" and characteristics of your setup. Subwoofer?....go class D on a budget :>
https://www.google.com/search?q=class+d+amplifier&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-USfficial&client=firefox-a&channel=fflb#q=class+d+amplifier&hl=en&client=fi refox-a&hs=srd&rls=org.mozilla:en-US
fficial&channel=fflb&prmd=imvns&source=lnms&tbm=sh op&sa=X&ei=aIzsT5ukKu306AHNxp3wBQ&ved=0CFEQ_AUoBQ& bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=3e94936e9ccb b820&biw=1680&bih=985