Robert, it sounds to me like you live your whole life to please others and that you come last. If we all listened to the extra tone not vocalised from our spouse and analyised every response, we would all be puppets without any voice or desire of our own. I apologise for being harsh, but from you said about your wife's response sounds like the epitome of passive aggressiveness. Take your stand, and do something for yourself for a change. Keep the mount and buy a second hand scope. If you give it up now and lose the opportunity for which you have waited so long for, and already started a journey on, it sounds to me you will live to regret it big time and harbour resentment. She told you to buy the scope - just buy the scope. If you don't go for it now, you may well be waiting another 40 years to have a go. Give yourself some happiness - I'm sure you deserve it. No one should have to wait that long to pursue something that has been so passionate for them.
$25,000 plus for a wedding?! That's outrageous! I'm assuming you are paying for the whole lot. Everyone I know, myself included and even the young-ens of today have paid something towards the cost of their own weddings. That amount would be a serious deposit on a house.
I honestly hope I'm not coming across too harsh Robert.

I'm saying all this because this post has pulled on my heart strings and I want you to be happy (even tho I don't know you).