Ya, Once you have an 8gallon pot or bigger, all-grain is as simple as a paint strainer bag.
To spend a little more money (and still one of the best options) get a cheap cooler. I bought a 48qt rectangular Igloo for like $19 at target. Remove the spigot, install a ball valve and build a PVC manifold for about $10 in parts. You'll have a full time mash/lauter tun for under $40.
I've brewed dozens and dozens of batches with just a single pot, and a MLT. Just collect your first runnings into a fermenter bucket while you heat your sparge water. Works fine. Sure stainless steel vessels, and automated systems are great (I just pieced together a HERMS setup), but they're not required for good beer, they just make it a little easier.