I think it depends on which "plan" you get approved on to be honest. If you get a starting CL of $1500 I think you would have a good chance of getting a higher limit. I have seen however than many seem to be capped at $3000 or $4000.
I had $6700 I believe about 5 years ago... Started at 1k and they did auto CLI over a few years as I spent money... I bought several different furniture pieces over the years which had financing etc. never really shopped in store for clothes or anything, JCPenney not my style.
I know it can be pretty high for a card like that. My mom has some outrageous limit of like 10,000 or 12,000 maybe even higher then that. She has had the card for like 20+ years and has also worked for them off and on for all those years.