The Warren Report has travel expense logs for Oswald’s trip to Mexico. Lone Crazed gunmen, don’t keep expense logs.
Neither do CIA/FBI/KGB/Mafia (take your pick) hitmen.
The FBI did examine closely Oswald's expenditures for rent, trips to New Orleans and Mexico and other living expenses,had an outside source of unexplained income. Likely what is in the Warren Report is an FBI recreation of how much Oswald spent on the trip.
LHO sure travelled a lot for an unemployed guy with no savings or a car who supposedly had no driver’s license.