<p>Can I Print models from Sources like <a href="https://www.thingiverse.com/" rel="noreferrer">Thingiverse</a> and sell them ?
I will be only charging the print costs and will provide full credits and attributes to the original creator of the model (with links to their profiles) in my web-page.</p>

<p>There are websites like <a href="https://www.3dhubs.com/" rel="noreferrer">3dhubs</a> where the seller will print any file the user uploads. Similarly I want to charge only for the printing services. </p>

I've informed myself a bit about this and found out the following:
It is good that you state the Name/Website or any Reference about original creator
Creative Commons absolutely requires this, even if you don't charge anything for your prints.
So, whether you are trying selling your print or not, you should still always do this.
You are not allowed to sell your prints
Creative Commons License dictates that you are not allowed to commercialize products that are based on any of their sources. This means, even if you are only charging the printing costs, you are not allowed to sell them, as you are profiting of their sources because you did not design the prints yourself.
For further information on this, you should probably check out the official page for this,
https://creativecommons.org/licenses/by-nc-sa/3.0/
I hope this helps, Max