When buying an amp for your guitar, it will serve you well to due your homework before you part with your money. I believe many times people know they need an amp and don't consider a lot more than the price, or maybe the brand name before making the purchase.
If you've been around music for a while, you're going to know the better names in the industry. Obviously, Fender, Mesa Boogie, Vox and many others are quality equipment. The point is, just because you know you need an amp of some type, and there's a Vox AC30 listed, maybe here on this auction site, for what you've determined is a good price, doesn't mean it's the right amp for you. More importantly, for your specific playing environment and requirements.
A good point to make here is this. About (3) years ago I was needing to get myself an amp. I knew that I only needed something to practice on here in the house, and possibly, maybe some day, in a slightly bigger area. I've always been one to spend money unnecessarily, and I was SO tempted to get myself an AC30 (see why I mentioned it before ? ), or one of the several Fender amps that just have that nice warm tone, beautiful sustain, and that good 'growl' right up to where it starts to give 
a little feedback if you're a little close to it.
Well, for one of the few times in my life, I let my common sense be my guide, and I bought neither the Vox or a Fender, even though I'd still love to have either...and I will one day! My money situation will have to be a lot better though before I make that purchase.
I ended up buying a new amp. I bought a great little Pignose G40V tube amp. It's got a ten inch speaker in it, and it does everything I could possibly want, and a little (lot) more. This little powerhouse has 2 - 6L6s, and 3 - 12AX7 tubes, 4 and 8 ohm output jacks, controls for volume, master volume, treble, mid, bass, and presence. The thing is, I paid less for this little jewel new, than I would have spent getting the Vox or Fender used!! Plus, I would have ended up with a big powerful amp that I would never use 20% of.
Don't think I'm trying to sell you a Pignose amp, or any other amp for that matter. I just know if you're more of a rocker at heart, it's easy to want to go with a little (lot), more amp than you'll ever use
Even this Pignose with a single 10" speaker is really more than I need, and the thing is, with 40watts, that amp will push a 4x12 cabinet!! Why would I want that big, powerful, sweet sounding Vox, Fender, or maybe even a Mesa Boogie, or a couple of others that come to mind (Marshall anyone ?)...because I'm a guy, so bigger is better!! Maybe not bigger physically in this instance, but they sure do have that BIG, BEAUTIFUL sound.
Seriously though, if you're just needing a smaller amp for practice, or even if your band is playing out, but just smaller venues, don't spend money you don't have to, and wind up with more amp than you need, Those 
Pignose G40Vs and Fender Blues Juniors sound mighty good.
But hey, in case you do maybe go ahead and get a AC30, a Fender Twin Reverb or some other classic masterpiece...if you ever need to sell it, gimme a call. 
