I don't really drink Champagne that much but is there a big difference between $50 Moet & Dom Perignon?

to me $20 bottle of hennessy tastes just like if not better than $50 bottle of Remy Martin VSOP.....so j/w if $50 bottle of MOET taste same as $150 bottle of Dom Perignon or even Cristal...are these 2 higher priced champagnes really that much better in taste