Are they giving you a place to live on top of the 20k, and is it furnished? Or do you just get a housing allowance? Because that would make a difference.

You *can* find a decent apartment for 4-5000 riyals a month but would have to search high and low for it, and at that price range may still have to invest in things like furniture and appliances (Air conditioners, washing machines, water heater replacements). That is, if you are coming over with family. If you are alone it would be easier to find a furnished place for around 5k.

Normally I would chuckle at this kind of discussion because I know many, many people surviving here and having a grand old time with far less. But, if you feel like you are giving up a great deal to come here, with your level of education and experience it sounds like a low offer that should be negotiated or passed over.