Have you tried asking your nearest brass band if membership includes the use of their instruments?
Many of the brass bands I've seen in NSW loan out Sovereign Euphs to their members.
When you order from overseas, often it's not practical to follow up on any warranty issues because you have to send the horn back to the dealer.
So you should consider the extra money that you pay by buying locally as insurance because you are protected by NSW's Fair Trading consumer laws.
If you do buy from overseas - ask them to remove VAT. In some cases (with used instruments) there might not be VAT applicable.
You will definitely pay an import tax to the Australian government - don't forget to factor that into the cost of the instrument.
If you are in Sydney:
Ed Diefes at Roseville have Eastman euphs
https://diefesbrass.com/collections/...nd-tenor-horns
Andy Yule stocks John Packer euphs
https://www.yulemusic.com.au/?Collection=Euphoniums
Both brands have good reputation in the "value for money" category.
I bought my Besson from Sax and Woodwind and they have excellent after-sale service.
https://www.saxandwoodwind.com.au/
I would chance a Yamaha euph from overseas if there were significant savings because their manufacturing consistency is excellent.
Good luck in your search.
Regards,
Jeff Ma