I looked around but ended up going with T-molding.com too. Partly because I could also get a router bit that I could be sure would match the t-moulding. I found what seemed to be approximately the right router bit in Bunnings, but it was metric and cost about $50.
The costs in $AU were:
$18.02 2x 20' red 5/8" t-moulding @$9.01ea
$21.87 Router bit (for t-moulding)
$12.12 Router bit arbor (for t-moulding)
$16.48 T-molding.com shipping
Total $68.49
I don't know what the exchange rate was at the time. Unfortunately the Aussie dollar kind of sucks right now. Shipping was fast, and the quality seems pretty good. It's divine to cut, for where you need to attach at curves.
Eh, probably not much help to you. But at least there's some figures. Good luck!