Work Visit Visa
The Work Visit Visa usually comes with a free, unlimited entry/exit visa. However, there’s a charge of 5 Bahrain Dinars (50 Saudi Riyals or $13 USD) to enter Bahrain for a weekend.
Iqama (residence visa)
You have the option to purchase single or multiple exit/reentry visa from operations when you need to leave the country. From 200 SAR ($54) for a two months single exit/reentry visa and up.
Check your visa validity through governmental site here.