I am thinking about it from little different perspective:
Personally I do not feel emoji domain names at all, from many various reasons...however:
In terms of close alternatives,
there is no close alternative to your "cloud emoji" in .ws
reasons:
a) it is single picture emoji domain names
b) afaik only .ws now supports large ranges of emojis
So if they are data/cloud oriented company and someone important from their marketing team got such idea (ideal scenario for you) so that they want to use this on social networks or for their VISUAL add campaign, there is simply no alternatives for them. They can not choose different extensions as different extensions does not support emojis (so far).
Conclusion: all depends on your personal situation. If 3k is lot of money for you, take it. If you do not care about 3k, and this amount of money makes no difference for you, give them 50k counter offer and hope it is a big company with lot of money and stubborn marketing team VP (so called "ideal end user")...in case of such large counter your probabilities of sale are reduced drammatically, of course. But you have very nice name, so think twice..
GL