Hi Markus,
I make my living in Nepal by my computer skills. We mostly build websites and offer related hosting, and sometimes some other computer related support.
I must say though that Nepali customers will mostly be shopping around for the cheapest (not necessarily best) deal, and try to discount the price so much that I don't want to compete with local companies doing the same work for local customers. Therefore for my customer base I mostly rely on foreign, European, customers. Which works for me, and also works for a couple of other companies with foreigner investors at the wheel in Nepal, with which I am in contact.
This is mostly outsourcing business.
There is a relatively strict list though which dictates in which fields foreign investors are allowed to set up their companies, and still keep 100% of the shares. If you want to work outside of this list, then you will need a partnership with a Nepali investor. That could also work, but can introduce trust issues.
Check out this rather extensive document by the Nepali Department of Industry on Foreign Investment in Nepal:
http://www.doind.gov.np/pdf/pmanual.pdf
The amount of money needed to set up a business is not fixed, but there is a minimum of US$ 25,000 involved.
If you invest less, you will not be granted the business visa you need for staying here full time.
For an investment of US$ 25,000 to US$ 100,000 you will be able to take a 1 year business visa which needs to be renewed each year. For investments of US$ 100,000 and over you will be able to apply for a 5 year visa, which needs to be renewed only every five years.
But eventually, to be allowed to set up a business in Nepal, you will have to submit a business plan which calculates for a realistic investment, and they will evaluate your plan for its feasibility. If the amount you plan to invest is in line with your plans, then it will be allowed. If not, then not.
Other foreigners have set up businesses in Nepal, some with more and others with less success. The scope of fields is so wide that I don't care for making a list. In my idea it's very well possible to set up a company and make a living in Nepal for a resilient foreigner. What sort of business totally depends on your interests, and where you see profits for you...
Hope this helps you some!
Kind regards,
Jorge.
PS. If you have more specific questions, then please use Private Messages instead of the public forum.