Low budget workstation dilemma in 2024

I have low budget (max 1700 €) and want to build my personal workstation for deep learning scope (mainly computer vision).

In 2024 make it sense to buy an RTX 3090, or should i wait for a second hand 4090 or price reduction ?

I'm in Italy and the hardware cost is almost 15/20% higher than USA.

Thanks for your help!

budget build computer computer vision cost deep learning deeplearning hardware italy low max price rtx rtx 3090 sense vision workstation