Not a Mets fan but we enjoy going to Citifield anyway. Here's the seating map:



I agree about choosing seats between 1st and home or home and 3rd. I went to Stubhub and found seats for the Oct 4 game for $67.85 in Caesar's Gold section 312. Here is the view from that section from Stubhub:



For the Oct 3 evening game, Stubhub now has a seat in Box 122 for $108.80. Here's the view:



So with your budget, you have all kinds of options. Does your bride share in your love of baseball? If not, I would advise going to Sunday's day game on your own and letting her have a blast on her own.