Money requirement depends largely on type of trek style, duration and trekking region.
If you are on Camping or Tea house trek all meals will be provide. You only need money for table drinks (alcoholic/non alcoholic beverages), snacks while walking (a few smaller shops are available along the trail in some areas) tips, souvenirs, hot shower (available in some places), domestic airport tax (usually 3 USD). For a two-week trek take about $100-150 worth in Nepalese rupees, more if you intend to buy souvenirs and drink lots of beer.
If you are on ‘GAP’ trek style you need to pay for all your meals. NPR 1000-1500 a day should be enough to cover your meals. We pay for your accommodation at mountain hut (tea house) along the trail and bear all the expenses of staff assigned by us.