I don't know if someone has suggested this or not, but for someone on a budget, this is an AWESOME gift! It comes from the heart, and not from the pocketbook. Make him a card, that says he has won a special weekend with you. Let him help set the date, but the details are all up to you.
Send the munchkins to grandmas/whoever for the weekend.
Make him a special dinner, spend time together and get to know each other again. Men don't admit it, but they DO enjoy this sort of thing, if it's in the right place and the right time. So I guess what I'm saying is, don't plan this weekend during a big game or on "poker night".
You can buy some massage supplies or some naughty games or whatever floats your (and his) boat, and just reconnect with each other. Children, especially small ones make it difficult to have that kind of time together. It's a good, inexpensive gift that he'll really enjoy. Just try to keep your plans flexible--there is nothing less sexy than "OK, 10 minutes are up, massage over!" :-) Good luck!!