Do things on top of magnets make the magnet heavier Say you have a magnet set to repel a platform (a really strong magnet) and then load that platform with 1000 pounds worth of stuff does that then get transferred over to the physical magnet 
 A: Mass of magnet $= m$, Mass of platform $=M$ and acceleration due to gravity $=g$.

Case 1

Here as you can see, the platform is levitating over the magnet. Since the whole system, magnet + platform, is at rest so the net downward force is equal to the net upward force. The net upward force is the normal force ($N$) and the net downward force is the force due to gravity. Therefore:
$$N= mg+Mg$$
Now if we had put an weighing machine below the magnet, then it would show us the value of the mass ($M_{\text{eq}}$) required to create the same amount of normal force as created by this system. Therefore:
$$N=M_{\text{eq}}g=Mg+mg\quad\Rightarrow \quad M_{\text{eq}}=M+m$$

Case 2

Now let's assume that we push the platform down with a force $F$. Then the force equation will become,
$$N=mg+Mg+F$$
And again,
$$N=M_{\text{eq}}g=Mg+mg+F\quad\Rightarrow \quad M_{\text{eq}}=M+m+\frac{F}{g}$$

Conclusion
Thus we can see that the weighing machine will keep on showing more and more weight if we increase the load. However, physically the mass of the magnet remains the same, no matter how much load we put on.

Image source
A: Short answer: The mass of the magnet is an intrinsic property and not altered. The weight of the magnet is though.
Understanding the difference is a key concept.
