QR20,000 Total - This is quite good, depends on nationality, Irish right? could get more depending on extra perks. Get them to cover housing costs as landlords are adding 10% a year to rental prices.

What are the standard benefit packages offered by private companies

annual flights/tickets are standard - circa 5-7,000 pa per person
Travel allowance 1-2,000 per month
Location allowance (if not Doha) 400-1,000 QR per month
"Expat allowance" (or whatever they may call it) can be up to 20% of basic.
End of sevrice benefit - should be one month basic per year worked
Housing furnture allowance (if not furnished) - 15,000-50,000
Who pays the water elec bills? can get 400QR per month to cover
Car loan possible, 0% interest up to 5 x your basic
Yearly bonus (1 - 2 times basic)
Yearly increment???
Schooling - if you need it get it sorted before you arrive....

What are the standard working hours for private companies?
Varies either 7-3 or 8-4. 5 days a week

What are the standard holidays per annum? between 20-37 working days