Unsure on costs, but there are meet and greet services, maybe hiring one of them to know for sure you have an extra adult to help move the 4 bags? Taxis and Uber officially mean going to the special lot. Theoretically, you could catch the LAX bus that stops at each terminal and just get off at UA, it shouldn't be jammed at T3, but I live in LA so don't have direct experience using it. https://www.flylax.com/en/lax-traffi...ine-Connection and https://laxtransportation.ridesystems.net/routes/