Your biggest money saver?

[pegkerr]

What one-time purchase has saved you the most money over the years? For me, it's my Krups El Primo espresso maker. Instead of wasting $3.50 for a cafe Mocha at a coffee shop, I can whip one up in the morning for a fraction of the cost. I have saved hundreds of dollars, perhaps thousands, with that one $50 purchase.

And you?

Cross posted to poor_skills.