I'm curious what you mean by "worth it?" Not calling you out on anything, but just intrigued by your position because, as the user above stated, you were really excited about getting an LCD-X.
In theory, your LCD-X and Oppo HA-1 set-up is an end game. You don't have to go higher because of even more severe diminishing returns. The HA-1 is a wonderful unit that has tons of features. The LCD-X is a headphone that can handle multiple genres really well -- and it's a fun and lively headphone overall. So, if you knew about the diminishing returns (~$300), why bother doing all this research and looking up good pairings if you couldn't justify the expense? I mean, you could have gone to an audio store or a headphone meet to see what the hype was all about.
I personally believe that audio hasn't substantially changed throughout the years and it's a relatively stable hobby (to the extent that one doesn't get caught up in the hype). Also having a good audio system allows you to enjoy music, movies, television, video games, etc. - and if you engage in these activities regularly, in the end, it becomes "worth it."
Then again, the journey is part of the fun. I think it makes more sense to do incremental upgrades rather than jump right into the big leagues because otherwise you don't experience different sound signatures and flavors. However, looking back, I would have done things differently if I had the knowledge that I do now.
But if you get the same enjoyment out of a Philips Fidelio X2 as you do a LCD-X, or you find that a $100 set-up is a personal end game, more power to you.
If I wasn't a collector/crazy hobbyist, I can see myself parting with a majority of my headphones, but I'd never give up the LCD-X. It's my favorite headphone (tied with the HE-6) and it is one of the best headphones out there for metal! So... sucks to see you parting with your LCD-X.