I am from a local uni MBA. Took it part time (3 years to complete).

Pre MBA - S$8k
Post MBA - S$12k
Now, 3 years post MBA - S$17k

I did not change my job throughout the 6 years. I just have a good boss and MBA does help me frame my thoughts in handling issues at work.

Overall, it is a good investment as long as you can make the most out of it.