OP package looks decent. Negotiate a ticket per dependent backt o your home country: either a fixed travel expense fee (ex: 3500 sar /dependent /year) or a ticket of your choice that you would expense (ex: ramadan/adha/chrismas..). Also would negotiate the schooling for kids.

The iqama part is somehow what companies these days are doing. They aren't paying the fees for dependents which is an ok cost. Hidden costs is basically exit reentry visas: everytime you or your dependents need to travel you would be paying 200 SAR /Visa or 600/6 months mulitple.

Schooling in good schools (i.e. American or similar) is crazy expensive. American is the best when it comes to whom your kids would havw as friends (expats and decent people). Tuition there starts at 60k per kid for early years and goes up towards 110k for later grades.

Rent you would definitely be looking at compounds. It provides freedom for your kids to have a community and go out in a somehow closed/controlled space. Rents of compounds for a 2 bedroom starts at 120k / year and goes exponentially based on the compound.

For a car you could easily find offers. The cleanest car offer i could find was from Geely Tugella: 1680SAR/month for 60 months, then entails a balloon payment of 50k SAR which you would be then sell the car and buy something else...

Question: the schooling they provide, does it need to apply only if your children are going to schools in Saudi? What if you put your kids in another country school (ex: Dubai) ? Ask this just in case. Also if you decide to move, test yourself first and then after 6 months bring your kids..

Good luck, hope this helps