The cheapest for me is to use a Double Edge (DE) Safety Razor. I use a Gillette Super Speed (Black Handle) and I get razors at Walmart. They are Wilkinson brand and a pack of 10 is something like $1.74! One blade will usually last me for about a week. Although, some people switch out their blades everyday, at $1.74 for 10, it ain't that bad! You can pick up a new DE razor on the interwebs (just google DE razor) or you can buy vintage on ebay and check craigslist. I hope this helps!