It's not 100% known yet but more than likely just a once off. Also more chance of not having to if you apply before they stipulate that as a requirement.
I'm in Queensland and applied at the Canberra Thai consulate. Applied about 4 days ago and the application is pending approval so hopefully not much longer.
Also the application process was very easy I had it done in less than an hour. Just ensure all the documents are in order and in PDF or JPEG. All mine were screenshots and unable to upload so I had to convert them all to PDF.
How much is a vasectomy? My application is still pending but I just used a proof of funds certificate from my bank that shows the current balance. Very easy to get just requested the the banking app and received instantly.