Camera dealers are all different, with different stock requirment, and local sales trends.
The Nikon adapters i have for instant, are NOT a QHY product, and only get them in as people need them. I do not normally stock them.
You also have individual people making their own adapters for sale.
Suprisingly, these adapters are not a great selling item. Everyone's needs are a little different, so its a balance of what to stock.
Theo
Theo this answer doesn't make sense

I am not asking for dealers to have stock but to list accessories on their websites with prices so we can order them.
This is about showing people who dont follow this forum, what you have for sale.
One example: You are on a website to buy a T shirt, but they dont show you what colours are available and no prices, if it was me as a potential customer, i would leave the site pretty quick.
For example, on your website you could show a stock standard Nikon and Canon adapter with prices, and put a note there that for customised items the price will be more.
The same is for say a filterset or individual filters, everyone here is asking for prices and availability and have to wait for answers.
I still dont know how much an HA filter is or an Canon adapter.
All this isn't even listed on QHY's website

I know for a fact that most astronomy shops have low or no stock of a lot of items and we know that, but we live with it (how else could we endure cold nights outside with the scope).
When i shop online, i see stuff i need and then see some more i need and buy it, if i dont see it i dont buy it (unless i see it somewhere else).
Enough from me,and i will not go into this any further.
Martin.