Comrade,

If someone takes part of what you earn and/or you can be fired then you are a member of the working class, Doesn't matter how much or how little that you make.  Here is Marx on this description of who are working class as not defined by amount of income::

“We shall assume that he is a mere wage-labourer, even one of the better paid, for all the difference it makes. Whatever his pay, as a wage-labourer he works part of his time for nothing.” “Vol 2.” Chap 6 p132.

http://www.marxists.org/archive/marx/works/1885-c2/ch06.htm

Or when speaking of merchants he is even clearer about how class is not determined by the quantity of one's income but of its qualitity, i.e. how is it that this income is obtained:

“In order to share in the mass of surplus-value, to expand the value of his advance as capital, the commercial capitalist need not employ wage-workers. If his business and capital are small, he may be the only worker in it. He is paid with that portion of the profit which falls to him through the difference between the purchase price paid by him for commodities and their actual price of production.

But, on the other hand, the profit realised by the merchant on a small amount of advanced capital may be no larger, or may even be smaller, than the wages of one of the better-paid skilled wage-workers.” Vol 3 p290.  https://www.marxists.org/archive/marx/works/1894-c3/ch17.htm

Here from another source c'est la meme chose: