The best advice I can give you is don't sell (unless you really need/want the money to pay for the honeymoon). I haven been married for 2 years but we were together for 4 years before that and when I started playing as long as my bills and our needs were taken care of I would spend money on DG. When I do want a disc now I sell discs that I don't want/need/use to pay for the new one. Someone said give and take.
Seems like the first response from any else who is married. Sorry single guys, you're pretty much out of the loop on this one.
Speaking as a married one, it's all about priorities. Giving her the benefit of the doubt (otherwise you wouldn't be marrying her), I'm guessing she has a reason behind her feelings.
She probably thinks you own too many discs. I'm guessing she's a non-DGer, and in that case, probably thinks owning more than say 20 discs is too many. If you have 100 discs, it wouldn't kill you to give some up. You'd miss them, yes, but, you'd get over it. After all, do you want to pick a fight over a disc you got in a tourney 5 years ago that you've never used?
Maybe a good compromise, if you don't want to sell them, would be to box them up and keep them out of sight. Or simply sell them. Weddings aren't cheap, you know.
Good luck with the wedding. Spending the rest of your life with the right person is far better than anything DG-related.