Kmart offers the LDR Industries Toilet Tank Repair Kit, model no. 503 1340, for $5. Opt for in-store pickup to avoid the $8.99 shipping fee. That's tied with our February mention, $9 off, and the lowest price we could find. It features a 9" ballcock, float rod, refill tube, flapper and ball.
Of note, Shop Your Way Rewards members will earn a Kmart credit with this purchase and may be eligible for additional credits and discounts.