It depends wether de name is associated with the gtld. For example I got thoose: Rubik.toys - Trip.Voyage
Perhaps worthless for some, perhaps catchy and rare for others, consider that on this world there are a lot of missunderstood sales. I see relation is perfectly associated with .online . I see chance on that What the others opinion? Let's see
.online renewal fee is high. Though this domain sound catchy and special therefore you can wait for buyer. I will prefer 3 .com instead of 1 .online. By the way clouds.security is available at regular price.
I am a big fan of .online, but personally I do not feel keyword "relation"...still, it can fetch mid XXX, while probabilities are pretty low for this keyword - so not really sure here, but if you can keep it with registrars where renewal for .online is cheap, then why not