Completed my first build in 2 days with parts that are bought with a $900 budget in mind. I tried my best to find high-end parts with a low price and did quite some research beforehand. Some parts are transferred from my old PC (hard drive/SSD, monitor, keyboard, OS etc.) which helped me stay within budget.
For budget builders, skip the SDD (optional: downgrade hard drive to 1TB) and use a cheaper 450W power supply, that should bring the total down to $1000 with minimum impact on performance. You can also switch the CPU with Ryzen 5 1600 to get similar performance at a lower price (suggested in the comments)
I think the natural red light from the motherboard and the white from the cooler matches pretty well with the case so I didn't invest extra on LEDs.
Feel free to comment any thoughts/improvements!