It depends on the year and what else is on my plate. Right now, the budget for travel is much smaller than I'd like, because I've been saving to build a new house on my property, and to help my son with college (I also had to replace my car much earlier than I'd wanted).
From the time he was 9 until he was 17, we did 4 trips to Europe. Two two week trips, one 9 day trip, and one five week trip. For the five week trip, I budgeted $15k, but spend $12k (including a Black Forest cuckoo clock for my parents, as a "thank you" for watching my dog).
Last year I only spent a few hundred on two road trips (one was a drive to Vegas with a friend, then a flight home, the second was a solo five day road trip to Utah-- two nights sleeping in my car, two nights in a hotel).
This year I have a 10 day, solo trip to Sweden and Finland planned for the spring (cost of flight+rooms+ferry between countries = $805, and 44 hours of vacation time. I could have traded a 12 hour night with someone to make it just 32 hours of vacation, but just taking it was easy, and someone will be happy for the overtime.) I have another $1k set aside to spend on everything else I'll need there (food, entertainment, souvenirs), but I don't plan to spend that much.
I'm hoping that I can continue to set aside at least $2k for travel until I get the house built. I can take 16 days off in a row, 10 5 times a year (every 10 weeks), and only use 16 hours of vacation each time, if I want (if I don't want to block it off, I still get 14 days off in that stretch, and can work OT if needed). Goal is to do at least one international trip every year until the house is built. After the house is built (which would mean I could sell my current house, or just explore some other options), I hope to do at least 2 international trips each year, with a much larger budget. I'm guessing I'd want to set aside at least $10k/year.