Well, including "free" stuff *is* part of working the budget, so I don't think it is unreasonable to include it as part of why a person thinks it is a budget trip!
OP - my idea of a budget trip is what we are paying to go for 5 days/4 nights in November for the five of us - Me, DH, DS13, DD9, and DS7:
We are paying an upfront cost of just about $2807.00 for our trip. This includes:
$628.92 - roundtrip tickets for the 5 of us, and one checked 60 rolling suitcase. Each of us will be allowed one free 16X12 personal item (the kids will have school-sized backpacks as their personal item, and DH and I will have bags the size of a large laptop case)
Free - car ride to and from the airport so we dont have to pay train/cab fare or pay to park at the airport.
$92.00 - Rental car (full-size) from Hertz for the 5 days we are there DH works for the Hertz corporation, so we are using his employee discount
Free
DDP plan, DD will be counted as an adult since she is almost 10, so there will be 4 adults and one child on the plan.
$2087.00 4 night stay at POR in the Bayou rooms to accommodate our family of 5, and 3-day park tickets
Other costs associated with the trip will be:
$150 3 $50 gift cards, one for each kid for spending money/souvenirs
$500 tips and other incidentals, extra snacks/meals not on the DDP, souveniers
$200 pre trip items, like a new pair of sandals or shorts/shirts if the kids happen to outgrow something. Not really counting this as part of our trip budget since they will wear/use the stuff at home, too, but I thought Id throw it in there anyway.
$25 paying DS13s best friend to come over 3 days to feed the cat.
Grand total: $3682.92