I'm currently looking into a DSLR camera system. Amazon seems to have it on the site and I can take advantage of the Prime service that I have. With a quick thought, I have the INK card but need to start getting giftcards in order to maximize the 5:1 ratio on earnings. Since the camera is going to cost me around $2k and the lens will be another $1k, this means I need a lot of Amazon Giftcards.

Whats the maximum giftcard value I can get at a office supply store?
Should I avoid Amazon gc and get Visa Cards instead?
How should I avoid being flagged by Chase? I dont' want to loose my credit cards because I'm trying to extend on the earnings.