Nested If / AND statements

I am having a hard time with nested if/and statements. I am working out a commission structure for retail store employees who sell spots on trips, and they get more money the more full the trip is:

$25 for any deposit for any trip that is not yet a “go”
{TTLSignups}<{GO}= $25

$50 for a trip that has met the minimum “go” number
{TTLSignups}={GO}= $50

$100 for a domestic trip that goes full
{TTLSignups}={MaxPax} AND {Region}=“North America” =$100

$150 for an international trip that goes full
{TTLSignups}={MaxPax} AND {Region}!=“North America” =$150

Here is the formula that works, but I want it to also show that if the trip is full and the {Region} is anything other than “North America”, it should return 150.

IF({TTLSignups}={MaxPax}, 100, IF({TTLSignups}>={GO}, 50, 25))

Here is the formula that DOESNT work:

IF(TourStatus=“GO”,50,
IF(TourStatus=“Needs More”, 25,
IF(Region=“North America”,100,150)))

Any help will be appreciated!

I think this adds the region check you want:

IF(
    {TTLSignups}={MaxPax},
    IF(
        {Region}="North America",
        100,
        150
    ),
    IF(
        {TTLSignups} >= {GO},
        50,
        25
    )
)

You nailed it, thank you!!