Comparing versions of the same verse can be enlightening, but also frustrating. By going to biblestudytools.com, for example, you can compare 25+ versions on the same page! Here's what I found by doing so with the verse in question. I've grouped them according to cognates of the same root words (e.g., pride, glory, rejoice, boast, etc.):
take pride in; then you can be proud; then he/you will take pride; be proud of what you yourself have done; be proud of your own accomplishment; cause for pride
he shall have glory; glorying; cause for glory
then he shall have rejoicing
reason for boasting; he will have his boast; reason to boast; what he has to boast of
don't be impressed with yourself [The Message!]
get the satisfaction of a job well done [New Living Translation]
happy with doing a good job
By looking at various versions, then, we see that the word pride is but one word to describe the phenomenon to which you've drawn our attention. Pride could also be translated legitimately glory, rejoice, be happy and boast.
Furthermore, the denotation and connotation of whichever word you insert into the verse in question has to be flavored by the larger context of Paul's letter to the Galatians; namely, the church's problem with Judaizers, of whom Paul said,
they desire to make a good showing in the flesh (v.12).
A point of pride for them was to get their fellow Galatians to become circumcised (v.13), not because they were scrupulous law-keepers themselves, which they were not (v.13a), but because 1) they wanted to boast of their success in compelling others to conform to their twisted ideas, and 2) they were afraid of being "persecuted for the cross of Christ" (v.12b).
That larger context, then, gives us the smaller context for Paul's mention of pride (or glory, or boasting, or rejoicing, or happiness) in verse 4, since the only legitimate form of pride (and there is one!) has to be based on one's own accomplishments, particularly those which flow out of our devotion to Christ and love for him and for others.
The Judaizers were guilty of illegitimate pride (or boasting, or glorying) because they were more concerned with others' works, especially the visible and fleshly ones (such as circumcision), than they were with their own. In other words, they were blatant hypocrites, holding others to a standard to which they themselves did not hew!
A sinful form of pride, of which the Judaizers were guilty, emerges when we neglect focusing on our own responsibilities and begin to focus on others' responsibilities and how they measure up compared to us and how we measure up compared to them. Such comparisons are fleshly, not spiritual.
The "two-sided coin" of bearing one another's burdens and bearing one's own load brings balance to the Christian's life. We bear others' burdens out of our devotion to Christ and our love for him and for others (v.2). We bear our own load because we all, as Paul said in Philippians 2, are to
work out [our] salvation with fear and trembling (v.12a).
This working out of our salvation is a joint effort of course, with us doing our part and God doing his, since
it is God who is at work in [us] both to will and to work for His good pleasure (v13).
In conclusion, there is a legitimate kind of pride, but even legitimate pride needs to be tempered or reined in by realizing God is ultimately the source of any and all of our accomplishments. Like Paul, our boast should be in the cross of our Lord (v.14) where Jesus bore the infinite burden of the sins of the world, including mine and yours. Compared to his burden there, our burdens here on earth are very light indeed!