Is it worth to mine with 1 GPU?

Hi. I want to start mine RVN. I had found all the rig, then I calculated, it all were about 1650€, but then, for personal problems, I had to wait. Now, in Lithuania, there is no left CPU and motherboard I needed. There are the similar ones, but the price is about 70€ higher and other parts are higher prices. Now, all the rig would be around 1900-2000€. I don't wan't to buy same thing about 300-400€ higher. I have an old PC, I just need to add more DDR3 RAM to it (max 15€) and new PSU (about 50-60€ for 500-600W) and, then I could run 1 or 2 GPU's. At first, I want to run 1 GPU, then, maybe add another. But is it worth to start mine RVN or ETH with I think 1080 or 1080Ti? I know there will come halving, ETH 2.0, so I'm wondering, is it worth, or should I invest to crypto and find other ways to get money?

I really appreceate if you rode this to the end. Thanks.