Thank you for submitting your suggestion
If I should analyze pros and cons of your idea, unfortunately I can only find cons.
Let's make an example, we set up an achievement like:
Make 50 posts => Receive 500 SB Points
Expected result
Users make 50 useful posts or maybe threads and in around a month they get 500 SB Points for reaching the goal in a fair way
True result
Users will start making spammy posts everywhere (easy target: Introduce Yourself section) and they'd gain 500 SB Points in 30 minutes for doing spam posts
Many other examples could be related to the example above, such as:
Level Up => Receive X SB Points
Since levels do depend on the amount of posts made, the outcome would be the same.
That's why, instead of thinking about achievements x SB Points, I introduced ways to legitimately gain them, described here:
How to farm SB Points at sbenny.com
But the truth is, a huge percentage of users who come here, aren't interested in contributing by helping the forum at all, so even if I'll keep adding ways to farm SB Points, I'm sure they'll keep asking for something easier and quicker. And yes, I'm ready to bet on this.