Well, that sucks that he doesn't want to use the Asha you want him to use. I can't say I understand fully, because I made sure my husband knew that if he ever 'wasted' money on a diamond, I'd say "no". Or return it. My husband just feels like he won the lottery having such a 'frugal' wife. (little does he know my evil plan is just to amass a tonne of sparklies over the years! hahaha!)
You could show him a diamond that's the size/clarity/colour equivalent to your Asha ACC. The price alone will freak him out. Or should.
I did a search for you on the Good Old Gold website under their diamond search... and found the prices were between $20,700 and $42,774 for a stone with similar colour grade, clarity, and size as the 7mm ACC Asha has. (I used the GOG site because I love their August Vintage cut. And it means they're all the same cut, so it standardized the quality on that level for my search purposes)
See it here: AV Cushion search
You've shown him what you want. You've probably tried to talk him into liking it. I'd tell him (jokingly) that a diamond is fine if he needs it to prove his manhood, but you want the stone size you want for your finger. And start showing him links like the above one. See how fast he starts warming up to Asha or Amora! lol!
I think if you sacrifice on size, or quality of the stone's cut/clarity just to get a diamond, you probably aren't going to be happy with it forever. So he'd be buying a diamond, and then later you'd still end up with an Asha or Moissy as an upgrade. So, perhaps he needs to take that into account as well in his budgeting.
In the end, I really hope you get something that YOU love to wear, and that HE is comfortable showing off.