I beleive this is the pricing structure they had or something similar
To calculate the cost of a Guild-directed trip, use as a standard unit of
either one person or 50 lbsof cargo.
Charge
I gp . per mile per unit overland ;
1 gp . per 10 miles per unit by sea.
A flat rate of 100 gp . per unit per Jump is charged, with a surcharge of 10 gp . per unit per mile of Jump travel over 50 miles.
I have modified these slightly - to reflect that trravelling in a group overland or by sea is not any "major" additional spell casting strain - controlling the weather for example would be the same for one and probably not need too much more for a slightly larger group - the larger group the more surcharge - at sea you are proteecting the ship as well so added into the calculation - this makes it more reasonable that a merchant would even hire them rather than through all profit away
I have keopt the jump charges high - do not want the characters missing the action on the way where I can
1 unit is a person or 500 lbs of cargo
1 gp per mile group rate overland plus a surcharge 10 gp per unit
1 gp per 10 mi by sea (group rate) plus a surcharge 10 gp per unit – including the ship
A flat rate of 100 gp . per unit per Jump is charged, with a surcharge of 10 gp . per unit per mile of Jump travel over 50 miles