Greg,
The reason for that is in what the keyboard can do. They Keystation is a simple keyboard interface. It allows you to play a melody or a song and is used as an input device to your sequencer or DAW, or Band in a Box in this case.
The Oxygen isn't really designed as an input device. Yes, you can use it as such, but it would be more for step entry, triggering a sampler, or simple editing. What it's PRIMARY purpose is for is to control a DAW, such as Pro Tools, in a mixing environment. In fact, if you read the literature for the Oxygen, it doesn't even mention the keyboard application until the end of the paragraph. It is more about the assignable controllers, sliders, knobs and how that works inside of whatever DAW (Digital Audio Workstation, if you didn't know) you're using.
In your case, I would look at this:
http://keyboards-midi.musiciansfriend.com/product?sku=703607VThis is a M-Audio 88es USB, at the very high end of your price range. It is a Factory Restock, which sometimes is called 'B-Stock.' What that means is that the factory sold it to someone, it was returned unopened because the company went out of business, or something like that. M-Audio can't sell it as new, so they look at it, make sure it works, and then sell it at a seriously reduced price marked as Factory Restock. It should have a Factory Warranty with it.
However, you might have a wait 20 days to get it, but for that, at that price, it's worth it.
This is a Behringer 61 key device that also will suit your needs.
http://keyboards-midi.musiciansfriend.co...oard?sku=702541This is new and in stock. People diss Behringer for being a rip off of everybody else, but I've always had good luck with their product.
Here is an Oxygen 49 for a not bad price. Forty nine keys will let you play, and it has control knobs and such.
http://keyboards-midi.musiciansfriend.com/product/MAudio-Oxygen493rdGen?sku=423008Finally, here is what I consider to be the best buy out there.
http://keyboards-midi.musiciansfriend.com/product?sku=709204VThis is the M-Audio 61es Factory Restock. This should give you everything you're looking for.
Again, I'm still going to bring up a keyboard with sounds, because of course, none of the keyboards listed above have sounds in them, and depending on what kind of software synthesizer you're using in your laptop will depend on how happy you are with the whole deal.
http://keyboards-midi.musiciansfriend.co...oard?sku=580591That's $159, and ships free. You'll need a USB to MIDI adapter to plug it into your laptop.
It's also possible to buy a used unit, a little better keyboard, from Musician's Friend. No warranty, but covered by their 45 day satisfaction guarantee.
http://keyboards-midi.musiciansfriend.co...sku=439620#used I wanted to give you this link to Yamaha's website for the YPT410.
http://www.yamaha.com/yamahavgn/CDA/Cont...amp;CTID=205100At the top right, there is a tab for 'Audio' and you can listen to the audio of what this keyboard can do.
There are two, one of which is available for $159.
Anyway, lots more to think about, Greg. By the way, please let us know what kind of software synth you're going to be using.
Gary