After doing allot of research, this is what I've found for cheap Trailing arms on the Summit (ZX chassis). I was told that the 2001 to 2003 arms are all interchangeable.
I like to have an xtra set handy - You never know..

Dennis Kirk (http://www.denniskirk.com/powervendor/lists/partlist.asp?serverid=nlSnow&Type=08&SubType=steercomp)- (Black) 64.99
Royal Distributing (http://www.royaldistributing.com/servlet/MiddleRedirect?page=146.html) (Black) 99.95
Ski-Doo - OEM - Local Dealer - 134.40 (after my %20 discount)
Rush Trailing arms (http://national-helmet.com/Products/Acc-Trailing%20arms.asp) - (custom colors) - $299.00/set $75 to replace/rebuild..

Please list more...

I can get Kimpex replacement ones for the Ski Doo oem #'s 505.070.521/645 and 505.070.522/646. They are listed for the Summit 600,700 for 00-01 and the 800,H,Hx,X for 01. Cost is $57.50 plus shipping.

I do some parts as a sideline and like to help out where I can.

If interested you can email me at carpetrx@ligtel.com


Thanks,

Tony

my experience w/ aftermarket is they break at the welds and if you take duct tape along w/ you , you can use that and duct tape a stick to your broken trailing arm to get you by, one of the guys i ride with, rode his for about 800 miles before he replaced it w/ just duct tape