Me personally, would choose a digital mixer. Especially like in your case , you said you are going to have several mics on. It helps to have nice efx for vocals. And they all have pretty good compressors and gate that would help tame those vocals and avoid feedback, of course if you know what you are doing with them. That is why lots of people run away fro digital mixers. There is a learning curve with each one of them. But, it helps if you are willing to learn, because benefits are rewarding at the end. But, we should go forward , otherwise we will end up on the trees again...hehehe

No matter what is your choice, try all your options. If stores don't want to help with trying, change the store. It's your money and they should earn it with providing you all you need to test these.
Let us know what you've got.

George

What about the NEW Yamaha MG series with the XU (they have with Effects and without, the XU is the model difference) (Excellent Effects, compression, and USB interface).
This models are with in your budget....check them out, I have a friend that got a Allen & Heat Zed series 14 ch, and we compare them earlier on a nice big ballroom with the same speaker system,
well, he owns now a Yamaha MG12XU.

I checked Behringer X Air XR12 and XR16, both are on pre-order, read some good reviews about Yamaha MG12XU. Will go and try it at local Guitar Center. After reading more about the capabilities about digital mixers, I think it's worth the waiting :-)

In a trade with a local music store. I ended up with this mixer..new..and new technology..a combo of digital and analog.

http://www.musiciansfriend.com/pro-audio...ing?rNtt=Peavey FX2 16 channel mixer&index=2

If interested, let me know. Can do better than manufacturers MAP.

Rog L

Rog ... looks like you streeeeetched that $500 budget a little, eh? ...
Best of luck with it ...