It's worth going, as you are very keen on his music, and it's his farewell tour. Maybe you could get cheaper tickets, for seats at the back? If you buy opera glasses, you will be able to see the stage better, and you will still be able to hear him.
In 2017, I heard Neil Diamond was touring the UK. Although I had been a fan for several years, I had never seen him live. I figured that because of his age, he would be unlikely to be touring much longer, (especially going abroad) and it would be my last chance of seeing him. To me, it was worth giving up the chance of going on a holiday that year. I would have regretted throwing away the opportunity to see Neil Diamond.
If you can afford it, and think you would regret not going, then you you should go.