I was in your shoe just weeks ago, I ended up buying a used mobo from the second hand market (much cheaper), well like you said even if you want to buy a new one this socket is hard to find already from retailers.

If you're just into gaming, I don't think there will be a huge improvement.

At the end of the day(if main purpose is gaming), what determine 99% of your FPS are just 3 things(cpu, gpu, ram). So make sure you pick these 3 core items correctly, while for the remaining parts you can use any choices u like