Applied for the promotional 0%APR for 21 months. I wanted to purchase 2400 in test prep for the MCAT but im a poor college student that cant fork up that kind of cash, this was my way to finance it. After applying I recieved the standard "we will get back to you in one weeks time", accompanied by a link to check the status of your application. My suggestion would be to call their application status line 3-5 buisness days after applying. Thats what I did, and I was approved with a 5500 CL which is awesome because I didnt want to use more than 50% of the CL for this purchase. My credit scores TU:765 EF:768 FICO:757 on all my CC applications I report an income to be 80k...... dont tell anyone lol. and I currently have only 13% of my total credit limit used. I have pretty high credit score because my first landlord taught me how to build credit and manage my cc acounts responsibly. Hopfully this will help give you a gauge as to what limit you might get approved for. As some other have suggested if you dont get the limit you want you can always ask to be reconsidered.
BTW only gave four stars because I have not recieved the card, used the online account access or even submitted the actual balance transfer yet. Issues can arise in all of those features. But the biggest concern for me was the opening credit limit, in this area I was very satisfied.