No, no ticket discounts through Disney Visa nor is a ticket purchase eligible for the 6-months no-interest.
OP -- as PPs mention, buying Disney gift cards at a discount and using those to pay for your AP one option for saving money on the purchase. Be sure to combine your gift cards because I think there is a limit of 2 per transaction (for tickets). And if buying multiple tickets you may need to do multiple transactions.
Another option is to buy regular tickets through an authorized reseller (like
UT,
AAA, etc.) and get that discount. Then upgrade those tickets to an AP. You'll have to do the math to find the best savings. Gift cards may be the easier route.