I want to hire a friend from the UK as a graphic Designer for my LLC. Is an H1B right for her? What if I can't pay prev. wage?

Your best bet is to talk the options through with an immigration lawyer.

Initially, the H-1B would be the first visa that comes to mind - assuming that your friend has a relevant, bachelor's-level degree, it would allow her to stay in three-year increments up to six years (beyond that, if certain green card filing requirements are met). You would, however, need to meet the prevailing wage requirement; the requirement doesn't disappear due to her willingness to accept a lower wage.

This said, there are still several possibilities. While a formal Prevailing Wage Determination can be obtained from the Department of Labor, the surveys used are online and an experience attorney can make a pretty good educated guess as to what the determination will say, to give you an idea. There are a few options available for making something like this work - different work hours, alternative wage surveys which may be lower than the standard federal survey, etc. An attorney can guide you on this.

She can start her own company abroad and work for you from abroad, making occasional visits here for business meetings, but she couldn't live here working for you as an independent contractor. Calling the arrangement an " independent contractor" or "vendor" arrangement, with her not being on payroll, is essentially irrelevant - this isn't the definition of employment for "unauthorized employment" purposes. Doing productive work for and under the direction of a U.S. entity is the real test - she would still be considered employed by you, and without a visa for that you would both be in violation. Unless she gets an investor visa to start a U.S. business, she would be violating the terms of any visa she use to enter on for this purpose.

To use an investor visa as an owner, she must meet several requirements - an attorney can guide you on this as well, though I think it would be extremely difficult given the situation you describe.

Speak with a lawyer - the H-1B may not be out of the question.