If you need to fix your chain on the side of the road during an extended trip, you still need the tool, even with a spare $5.99 master. If you intend to stay within pick up truck range of rescue, save the money. Then again, to repair the chain once your bike is home, you need the tool. It's Deja Vue all over again. No, you can use a abrasive cut off and a pin punch to repair the chain and insert another master, just not on the side of the road. Before I splurged and bought a cased chain repair kit, I just used a small bridge clamp to upset the pins on the riveted masterlinks, worked fine.
Bridge_clamp