I will appreciate honest answer.
From renting, you get nothing in the end. From buying, you can still resell your rig after six months - one year - eighteen months for, say, 3/4 - 2/3 - 1/2 of the original cost, all the components still within the 24 months warranty we get in the EU. The consumer market for GPUs has plateaued, in the last couple of years, the best pound-for-pound GPU is still the GTX 1070 with 8 GB RAM, which is and will be more than enough for learning purposes and applied domains usage.