Thanks for stopping by our offices to show us the 3D printing fruits of your student's labor! I mentioned this while you were here, but often, you can rotate the model before printing (in your case, in the MakerBot software) so that it doesn't need to print any supporting material.
Here's an example of this on thingiverse. https://www.thingiverse.com/thing:1559425
If the ship had been printed sitting on it's landing gear, the printer would be forced to print supporting material under it because of the space between the bottom of the ship and the ground. But flipping it up, there is very little area that needs to be supported. I hope this made sense!
For purchase of filament, our goto place is plain-ol amazon.com. We do suggested getting MakerBot branded filament for the MakerBot printer, though--i really seems to make a difference in the final product and isn't really too much more expensive!