yeah, install would take about 30 minutes - but removal of your old air box may take another 30 minutes if they had never removed one from the Celica before
also, it may take additional time to do the install if the guy has other customers walking through his door or keeps getting distracted by other things happening in the shop that he's gotta focus attention to.
plus, there could be more time involved than he had anticipated because the Intake
needs to be installed and then assembled... tube gets placed and then cone is added, then tube gets attached - unlike most other vehicle Intakes
where everything gets assembled and then tube gets attached and you are done