As I said, record in a studio or on a 4-track and mix in GarageBand.
Our bass player has a Boss digital 4-track, but I'm not sure that's what we'll use. I don't see the point in spending money on studio time if we can mix in GarageBand.
Lots of reasons. A professional's experience an guidance. In house mix down. Quality equipment. Who ever is singing will sound 10x's better recording at a studio vs. through a 4 track. Plus mic'ing a set of drums with just 4 mics will be tough unless you're doing it with an electronic kit.
It may seem like a lot of money, but the quality of the recording will be much better and good matters. My business partner used to run a large night club and it shows that this holds true: When people would drop of a five song demo, he would probably listen to 30 seconds of the first song and maybe 5-10 seconds of the rest of each. If you're handing in a recording for anything and the quality isn't good, it's not going to do you any good.
I think that you would be better off using the 4 track and garage band for just if you wanted to record practices or whatever.
I'm not sure what the purpose of the recording is for, but that is my opinion.
edit: Plus going and and buying the gear to do your own recording with can be much more expsensive than studio time. Most charge between $25-$50 and hour where I live. We charge $35.