Welcome to Cusco dear tourist
And now face on fact...
The prices of perurail (an chilean compania who has the monopol on travels to machu picchu) are completly insane

Cuzco-Machu to Picchu
Normal Train: US $105
Backpacker: US $68 (there are more but none cost less)
besides the fact that you pay like 15 times more than the locals (there is a seperate locals train) you have to face stupid arrival and leaving times
for example the backpackers arrive at 8pm and leaves at like 5am
so you have to take hostals for two days

FORGET WHAT LONELY PLANET TELLS YOU - ITS OUT OF DATE
e.g. there are no backpackers slot in the localtrain, the prices increased, etc

if you are low or no bugdet traveler there is one option the don't like to tell you in cusco:
Plan 3 days, take money with you, YOUR International Student Card (if you have one) and for gods love good shoes ;)

Lets go:

GETTING THERE: (day one)
Get a bus in cusco to Santa Maria (the leave in the south west of the town, any taxi driver should know it ... the cost for the cap is from center like 2soles (about 40uscent)
The buses leave at 8am and 8pm - they need about 6hours to santamaria where (event at night) smaller buses wait for passengers which will bring you from Santa Maria to Santa Theresa)

i would recommend driving at night.. this way you save time.. but dont expect to get a lot of sleep at night - in santa theresa you can get a basci breakfast and the have small sleeping places - dont buy bananas - there should be plently in the first part of the way to find (steal)

The first bus costs you 15 soles the second one 6soles - together about 4 dollars

From Santa Theresa there are two steps to take...
The first one is a 1h30 walk until the electricity plant - you can skip it by taking a bus for around 5 soles, but the leave not before 10am (so if you arrive in the morning you can save money and time by going for yourself) if you have to go over the river on a bigger metal bridge you are correct.. but actually the way is stupidproofen and everyone you pass can tell you how to go

When you pass the electricity plant you have to follow the railtracks, its like 2h30 hours more to go.. you never have to upwards, you have beautiful views, and you never have to think to much about which way to go.
Not many trains pass the track, its only used by the powerplant

You should arrive in aguas calientes (the small city where the trens stop)

STAYING THERE:
a cheap hostel is el caminote, you come too the city, get to the road where the railway tracks and all the restaurants are, follow the tracks to the left (away from the mercado and the trainendstation) its on the right - 8-12soles a night

you can find cheaper food in the mercado, a menu (soup and maindish with drink) cost 4-5 soles, you can find fruits and veg. for your walks there too, the prices are at city average.

BUY YOUR MACHU PICCHU TICKET IN AGUAS CALIENTES
YOU CANT BUY IT UPWARDS!
it costs 80 soles for everybody, if you have a international student card it costs 40soles

GET TO MACHU PICCHU (day two):

the tourist bus costs 6 dollars,
you can also walk, its about 1,15 hour upwards on an infinite number of stairs
if you want to leave early (like 4:30) take a light with you, its darker than in satans ass (for those who have been there)

the first tourist bus arrives at 6am and they open at the same time.
you have to show your international student card up there! (remember you already have to have the ticket)

i managed to get the student discount without the international studentcard, but it costed a lot of acting downwards and especially up at machu picchu


GET AWAY (day 3):
I RECOMMAND TO TAKE THE SANTA THERESA WAY...
so stand up early (4am) and get to santa theresa, there is one bus that leaves at 10:30 (and usually no more) - you can catch a bus at the electricity plant to save time and way
You should be back in cusco at night!

as i said i recommand this way home.. there is one other...
you have to leave aguas calientes and follow the tracks of the tourist bus, 28 kms
we did this.... ITS NOT FUNNY TO WALK
all the track is full of stones that slow you down, if you have bad shows its a pure torture (i had)
the views are not a bitter nicers, actually you feel like in a loop because you see so many times the same
if you need to save time, leave aguas clientes BEFORE 1pm (at yours machu picchu day) and hurry - you should arrive the so called "82km station" at night fall - take lights with you and pray for fullmoon - its a about 6-7 hours walk
you can sleep there in the village (piscacucho) and get back to cusco by passing some other citys (it costs about 10soles all together)... BUT THIS IS BY FAR NOT AS FUNNY believe me - if you have this half day to spare go back via santa theresa (where you may even sleep for free in the place you do breakfast)


anyway you can save a lot of money this way (about 60-100 dollars)