Hi,
Costco do not supply their aids through HSP as they do not release their software for other clinics to use, which in Australia is a stipulation for the clinic to have access to the hearing services subsidies.
Specsavers on the other hand do allow this so if you were to get your aids at Specsavers and transfer to another clinic that clinic can get the specsavers advance software to adjust the aids, hence why their aids are elligible for Subsidies under HSP. They are not ‘locked’ to specsavers clinics for adjustments
The bluetooth television devices which connect to advance are a rebranded signia streamline TV device for the advance range made by Sivantos (Signias parent company) and a rebranded phonak TV connector made by Sonova (phonak / unitrons parent company).
At present there is a global shortage of the Sonova TV connectors so even if you did want to order one you would not be able to and sonova cannot give us an answer on when they will be available. The bluetooth transmitter from JayCar may work with the Advance made by Sonova as this brand uses a bluetooth classic protocol, although sometimes there is latency with these devices - I also had a patient connect their hearing aids directly to the TVs bluetooth with no intermediate device, although am guessing this would vary across different TVs too.
Generally I tell people to see how they go with the hearing aids alone first, and if TV is still an issue to come in ang get a TV transmitter - They do work very well and will provide the best transmission of sound, but who knows - you might find that the hearing aids work well enough on their own!
Also - last thing to consider is that the advance made by Signia will only stream audio from an iPhone / IOS device (made for iphone technology) where as the advance made by sonova will stream audio from both android and iphone - Although if you have an iphone personally I prefer the made for iphone technology.
Hope that helps.