You are not required to have an AR15, and 6K is really high. I'm full time at OCSO and when it was time to buy a new belt I went on Ebay and bought everything but my holster for $50. When I went through as a reserve in 2000 I spent around $2,300 for everything but the cost of ammo was a lot cheaper then. Just go out and buy the minimum. There are also other departments out there that will supply you your own equipment.
It was made clear to me that an AR would be a requirement for OSCO. It's not required day 1, but atleast by the time you qualify after a year or so. Would have to pay for the uniform, buy belts, holsters, cuffs, ect. A lot of the newer recruits verified that when I asked them about it, so maybe things changed in the last year or so?
The AR wouldn't be that much of a problem for me. I have a couple and really would just need to buy a Glock 22 and another shotgun, since I wouldn't want to use Benelli I have at home for duty. And it's really not that I can't afford it, I just have issues with having to supply 100% of the equipment on my own dime when I'm already investing 6 months of training and volunteering 20-30 hours of work for free. In the end, even spending potentially a minimum of $2k is a bit much for someone not looking to go career in LE.