Investing in items that you get from BfA content can be a good idea. With Shadowlands players will spend significantly less time in BfA zones, and many items will be much rarer. This can lead to price increases, so if you have extra gold and a long term view you can potentially make some good investments.
What are we looking for
There are two characteristics we primarily care about: rarity and cosmetic value. All power increasing items will most likely not be relevant anymore. Cosmetic items will still be relevant however, as they never really go out of fashion if they are cool.
When it comes to rarity the biggest factor will be an item that is obtained from some type of gameplay that players will play significantly less once Shadowlands rolls around.
Best item groups
There are two great item types in BfA I want to highlight here. The first one is of course all the various world drop mounts and some related world drop items to obtain mounts. The other group is items from island Expeditions, particularly the highest price pieces.
BfA has a decent amount of world drop mounts. They typically drop from any mob in a single zone. Right now players farm these mounts with 2×4 farming. Of course there are likely multiboxers doing this as well. Hopefully the supply should fall significantly as players stop 2×4 farming and prioritize Shadowlands level farms.
In addition to this you have the Abyssal Fragments for the Nazjatar secret mount that I talked about in this weeks podcast. Below you can see a list of all of the tradeable...