Why do something simple, when there is a complicated way?
Ryzen 7 2700X | BeQuiet Dark Rock Pro 4 | 16GB DDR4-3200 | MSI X470 Gaming Pro | MSI GTX 1070 Gaming X 8G | 500GB / 750GB Crucial SSD
Fractal Define C | LG 32UK550 | Das Model S Professional Silent | CM Storm Xornet
Necessary?No but sure it helps with the loading times.It's awesome for mmos.In Wow i went from 6 sec loading time to 1-2 sec.I got 80 gb Corsair ssd.
An SSD is about as necessary as a fast CPU, and fast GPU or any other premium component.
It will significantly improve your quality of life while working with the PC in almost every way. If you're spending 1200 Euros on a PC it would be stupid not to invest a fraction of that money into an SSD that will be much more noticeable than the 10 more FPS your premium GPU will offer you vs. a midrange GPU.
So yes, in a 1200 Euro PC I'd consider an SSD "necessary"!
You don't necessary need to have it, but I really recommend you to give it a try. If you don't want to spend a lot of money - get a 60GB SSD - it will be enough for the OS and a few programs. But if you have some money to spend - I would recommend to get 128 GB OCZ VERTEX 4 (Sorry I can not post links yet)