I have a Beverage Air BM23 SS. This is the all Stainless Steel model with the optional 3 tap tower. I just got it and am new to all of this but I should enjoy it.
It was one of those things that I wanted for a long time and finally stumbled across a deal. I found it on a local auction site and bought it for $206. That is with a 20# CO2 Cylinder, Dual Regulators, a US San Key Coupler, a German Slider Keg Coupler and some strange chiller system for soda.
The only thing wrong with it was it needed a good cleaning. Being Stainless it cleaned up really nice. It also needed a new relay/overload on the compressor. She is running like a champ now. Total cost so far $246.
I have a couple buddies that own a beer distributor company. They said to stop by on Friday and they are going to replace all the lines, faucets and hook me up with some tap handles. It should be a pretty good system when all is said and done. The Beverage Air is a little bigger inside than some of the other small systems out there. I can fit 4 cornelius kegs in this unit.
I guess the one thing I would say to keep in mind is to watch what comes with the fridge and keep in mind that it a lot of times this isn't a turn key system. You will still likely need a CO2 tank , regulator and keg couplers. You may not need all of them but ask. For new stuff you are going to look at about $100 for a 5# CO2 tank, $50-70 Regulator, couplers are $35-80 depending on what you want. I would say they rarely come with couplers as they don't know what you are planning on putting in the fridge so it doesn't make sense. If you are going dual you need one for each. You may also need some lines but that is cheap so I wouldn't worry about that as much. Oh don't forget about the beer line cleaning kit. I think they are about $50.
So when shopping look at what comes with it and adjust your price keeping in mind what is actually needed to start using it. This will help you identify what the best deal is as you could come across what looks like a sweet deal but needs another $200-$300 in accessories to get to the point where you can pour your first beer.