My high school offered CCNA, A+, MSDN and a couple other certification courses when I went there (i guess that would be about 5 years ago now). I took the CCNA and A+ courses mostly just to pass the time, and never did go for the test, but the practice tests I took led me to believe that I would have gotten both.
That was over the course of a school year at about 1.5 hours a day, 5 days each week, and was admittedly taught in such a way as to make sure that even the slowest in the class could keep up It could probably be done in a couple of months if you were in it for 2 hours a day, 5 days a week since it would probably be faster paced. For the CCNA stuff, we got a lot of hands on experience since we had a ton of routers and switches in the lab that we would configure and fiddle with.
$6000 strikes me as awfully steep, unless of course you are living in an area where the average income is something like 20x what it is near me (most all the Comm College courses around here I think run $300/semester or so).
Also, although the certs are important to have, will you definitely see a solid return on that $6000 investment in a reasonable amount of time? I mean, if having them means your job will pay you more money and increase your annual income by like 10G, then yea, save up for it and go for it. If your job doesn't have a position available for you that will make use of that knowledge (with no experience) then you just tossed $6000 down the hole since last I checked, CCNA cert is only good for 5 years before you have to retest.