Printer Cartridges are surprisingly costly. As an alternative, you can get it refilled at a store. The cheapest and effective alternative though is to refill it yourself. All it takes is a bottle of printer-ink and a syringe.
Step 1: What you need
1. Printer-ink. You can buy it from a computer store. In Bangalore, you can buy it from an ink-refill shop at the entrance of SP Road, near City market.
2. A 1ml disposable syringe. The smaller the needle, the better.
3. Your printer cartridge. My printer uses a HP56 cartridge. But the refill method is same for most inkjet cartridges.