price on tilt/motion sensor backup siren

any can tell me where i can find a good price on tilt/motion sensor backup siren??

websites??

what to get what not to get??

I buy a lot on ebay (which is risky), but I have had luck doing so.  Most everything that I guy works like new.  I always try it before posting feedback the seller.  It's always good to verify that everything works first.

You can also check out this site:   http://autotechs.com/   Their prices are fairly reasonable, but they are a retail outlet, so they prices will not be as good as if you can get the stuff wholesale.

Good luck!