I would sell them altogether.
Im unsure on prices however. I generally think a good by is below 1/2 of original price.
Perhaps start bidding low so you know if people are interested. And set reserve at what you want. If it doesn't sell first time you can always lower price next time.
If im unsure on prices for an item i will put same items on my watchlist and see what they go for to help me get a rough idea