Hi, Here's my take on the computer desktop speakers.
Low end: ~$30-80
Mid: $100-$200
High: $300 and above'ish
This is my take on estimate of different price ranges. The thing is the price is not necessarily fixated to those low/mid/high-end speakers. But I would say avoid the cheap brand speakers. I use to own Logitech Z-2300, which i bought for about $110 2 years ago. For the price, its one of the bette computer speakers out there with strong bass if you're into hiphop and things and want to shake your room around a bit. However, sound quality wise, you could find something better if you pitch in more money. In fact, I just sold my speaker for $60 and now i'm looking to buy new speakers. I agree that going high end computer speaker is not worth for everyday users. My recommended range is about ~$120-200'ish. Here are some of my suggestions for the midrange speakers:
Logitech Z-2300 (if you want boomy bass)
Klipsch Promedia 2.1 (bit better than logitech in my opinion, more punchy bass, but harder to find)
SWAN M10 (bit cheaper than Logitech but has much better overall sound quality; has a subwoofer that is designed to be put on the same level as its other speakers in order to produce the right bass sound, which i think is a bit of pain)
M Audio Studiophile 2.0 (good sound quality, bit more expensive than swan, doesn't have a sub so some ppl think that bass might be in little weaker side but alot of ppl say it has enough punch sound)
Aego M speakers (super small form factor but still produces good/loud sound, has a 90W sub which I think will produce good amount of bass, but hard to find, only one website i know sells it online (www.stereo-link.com) and is expensive
As for myself I'm leaning towards M Audio Studiophile 2.0, Swan M10 and Aego M.
Some of the high end speaker producers are M Audio, Audioengine, and Hi-Vi Swans.