The boots and the shade weaver embrace will be popular in the future (popular in that somebody or you will want them to use). The Shadowmane, probably popular for collectors as well. I think some of the decor such as the mirror might be popular as well.
This is a problem I’m bumping into - I’ve been having to pick out reward items as I near 1,000 points. The boots are easy as I have several characters that can use them. I’m going with things I will actually use, and this event seemed to have several.
Edit: wasn’t sure if you were talking about for yourself or to sell In the future. I have at least one of all the items from the event that I mostly want, and so now it’s equipping my secondary characters with things like the boots and maybe a few more decor things.. The Shadowmane might be a good investment but that’s a lot of points if you don’t collect such things. The 50% SDI books for a few characters as I don’t have anything like it.
If you asked about something to sell in the future, I…would not be sure. I would expect the boots, embrace, and book to hold their value and then some. Maybe the Shadowmane. Towards the end I will have to pick things I think can sell, but a lot of people would already have them.