I let my singer use one of my guitar amps to sing through at practice and the quality really sucks for vocals.

I know there are amps for vocals but what brands are the best and how much are they usually?
Q is for Cheese
Usually an inexpensive portable pa for home practice.
If I'm performing, the gig usually supplies a sound system.
The best is a PA system.
Another solution is the use of a keyboards amp.
^this, i use a old keyboard amp for vocals and it works just fine