That is a lot of money.. You should check out "Rising Star" It is located at the old airport area. My nephew goes there and he seems very happy plus he has learnt a lot in just three months, April to June. July & August they were closed for summer and would reopen in September. They charge 1600 riyals per month for play school but I think it becomes less once the child goes to KG..
p.s The school is run by British management & teachers are Westerners too.