Sometime ago, I have written a post about shared hosting price war ended . It is, however returned on 1st May 2008. Some large hosting company like Hostmonster, IXWebhosting, StartLogic and Lunarpages are offering the basic plan as low as $4.95/month.
To be qualify for this new low price, you have to sign-up for 2 years plan, which mean you have to prepay 24 months upfront. Plan comes with free domain registration.
I am not sure existing customer can enjoy this rate, but you can try threatening them by leaving to another host, see if they are willing to offer you a good rate :D.
Any how, if you are happy with your current host, stick with them. a good quality hosting is worth paying for.
Check out my update list of good cheap hosting.