Beautiful place, it's on my list too!
It's completely obtainable and within reach. One of our engineers went there 2 years ago and he said it was amazing.
He and his wife flew into Lima and spent a few nights there and then took the train into the mountains where they stayed in a nearby town and then did the trek into Machu.
They said hotels and food were fairly cheap and the people were really friendly and the area is safe.
The only things to be concerned about is altitude sickness (the elevation is very high) but there are ways to prevent it and meds you can take along just in case (both of them were okay, his wife felt it more than he did, they are in their early fifties though).
the other thing is the red tape- to go see it you have to 'apply' ahead of time for some special permit or visa or something?
You will have to look into that.