I always thought it was:
Anything sent via courier ie. Fedex etc.. some courier service its max limit was $200 AUD.
While anything via post office ie. USPS, AustPost, EMS, etc. max limit has always been $1000 AUD.
They are great, well worth the money IMO. Getting a second set of rims for track days with semis on em so I dont have to rip up the T1Rs.
235/40/18 for T1Rs might be about 350-380 per corner I think.