Low cost and good performance ?
AMD Zen 4 cores or more cores if the price is good and not use high watts.
Nvidia GeForce GT 1030 is fast enough to video enconder, playback and for basic simple CUDA for render or others software using that API. PLEASE confirm if GT 1030 have NVENC if not have try to use an GPU from 700 series ONLY if you will use to video enconder, playback and if simple gaming emulators. Using an powerful only to simple software waste money and energy.
8 GB in 2 X 4 GB or only 1 8 GB module. You can use 2 GB or more for temp folder and also Linux if enabled compress memory RAM being easy to have 12 GB system memory in memory modules before write swapfile in disk. Use RAM with dissipation or use thermal pads.
1 SSD disk for system and 1 HDD for data, video and other softwares. Use tempfs for temporary files avoiding useless write in SSD.
Gigabyte mainboard are good.
Linux distro using an very light desktop .... Lubuntu use 384 MB and after installed nvidia driver use 484 MB. Others distro use more of 1 GB RAM.
An good PSU ... not need high watts capacity an 450 Watts is enough ... if you wait to play or use powerful graphics cards choice an PSU not less of 500 Watts.
Corsair 450 watts line are well durable.
PSU with high watts capacity using less of 100 watts the components will have long life
About DVD or bluray I not known exactly one good drive to say about ... Pionner was very good in DVD. Have bluray drivers that not open some types of bluray disc.
Possibly that machine in full load will use less of 150 watts if the CPU use less of 50 watts.
Avoid windows or change the specification above if you wait use windows for some work software.