On the marketplace, some sort of wishlist or “saved for later” would come in handy for saving potential future purchases.
Hey there!
This has been requested numerous times and is being looked into by the staff. =)
This is a feature that I have also noticed a need for.
While this may have no significance here, in old time MMORPG dev speak, “being looked into” means “don’t hold your breath.” 
I can’t argue with you on that. =P
I’m slowly adding features to the marketplace tracker at https://services.gamemak.in . Better wish list support is on the long term road map, but for now you can track assets you’d like to… keep track of.