Your budget should first consider accommodation and food,
which is an expense that goes hand in hand. Most guesthouse rooms aren't very
much, but the most money that you will pay for is the food that accompanies the
lodging. Prices for room go from free to up to $5 a night. It's per room, so if
you bring a friend, you can certainly save money that way. Those types of rooms
aren't typical. The average price per night is $2-3/night.
For your food prices, those will be cheapest when you are at
a low elevation or near a road. You wouldn't expect your porter (the ones who
carry your belongings, equipment, and food) to charge you a small amount for
carrying your food for a long period of time up whichever peak you are on. If
you intend to eat candy, soda, and alcoholic beverages, those can really mess
up your limited budget, as they are more expensive than local food. Local food
will definitely be cheaper.
Camping can be a bit expensive to prepare for, with all the
logistics and equipment necessary to enjoy that particular part of the trekking
experience. If you want to save a bit of money, you can just explore the
guesthouse treks. Be sure to use whatever gear you already have, like shoes and
a backpack, rather than buying new items. If you did want to prepare after you
get there, there are gear shops in Kathmandu. If you want to get items like
down jackets and sleeping bags, you can rent these types of items rather than
buying them outright. You want to prepare for cold and rainy weather, because
there's some of both of those. I'd recommend bringing a sturdy pair of hiking
shoes, because you don't want to have to replace them while you are trekking,
as that can get quite expensive.
Make sure you have a way to get to your trekking locations.
The cheapest option is the buses in Nepal. If you want to get there faster
though, Jeeps are better because they don't have multiple stops.
If you don't want to be lost, be sure to hire a guide who
knows the area. Be sure to ask for the credentials, because the guides in Nepal
have to go to a guide school to get qualified. You certainly want a guide who
has trekked in the same place several times over, so they can get you safely to
and from your destination. The standard rate to hire a guide is around $30/day.
If you go off the tourist track, that price goes up. Porters will charge around
$10/day. Remember, it is customary to tip your guides and porters at the end of
the trek. If you're a good hiker, you could save some money by not having a
porter or guide.