Hello everyone,
I am a new rider in this world.
I have been riding for around 6 months, 1-2 times a week for 40-60km each day and 2000m up /down, marathon or XC style(sorry for my English). Also 4 days of gym or static for extra work. 

However my bike sucks big time. I have a 26" supermarket bike which was around 199 dollars.

Now I want to buy a new bike but I can only spend around 500 dollars(I am still in college and don't make too much money).

Would it be a good idea to create a new Chinese bike with that kind of money? Should I buy a 500 dollars bike around here and then upgrade it with Chinese components as I get more money?

What do you recommend me guys?
Thank you!