It doesn't sound "grand", but I think that you can never go wrong with a night away from home, out of your usual surroundings--dinner and a hotel. Take a bottle of Champagne or sparkling wine (cheaper than getting a glass in the restaurant) to your room.
Find a hotel that's within walking distance of your favorite restaurant (if you don't want the hotel restaurant). If you can, go early and set the room up with rose petals. (I know where you can get a big bag of them for really cheap.) If you buy the least expensive thing at Bath and Body Works, you can still get some nice samples. Maybe you buy a candle and get some body fragrances as samples. Set the Champagne to chill in your room. When you and your husband get there together, you can drink a toast to your anniversary and to his new job! Then, you go to dinner...and return.
I've actually done that a few times (for us and for others), and it does not get old. I don't know what "inexpensive" means to you, so I hope that this is not over budget. I know how that goes.
Happy anniversary to you, and congratulations on the new gig!!!