That GPU was first released in 2018, and can be had for ~$1500 today. The computer as a whole sounds exactly in-line with what a lab would have as an old spare machine. The student is lucky for sure to have access to such an institution, but it's not like he had rich parents who casually handed him $10-$20k. Much more likely he got access to Caltech resources because his exceptional talent caused a professor to take interest in him:
"I would like to acknowledge and thank deeply my mentor Davy (Dr. J. Davy Kirkpatrick) for introducing me to astronomy at IPAC and providing guidance throughout this project, aiding in data analysis and the collection of known objects for the test set."
[0] https://iopscience.iop.org/article/10.3847/1538-3881/ad7fe6