Ruling on the Black Hole Arrow

[Ryujin]

Saagael's concept seems reasonable ... however fail to see the Weapon-of-Mass-Destruction facet since RAW states -ONLY- the bag and hole are actually destroyed in the resulting dimensional implosion, while everything else within a 10ft radius is planeshifted to a random location on the Astral Plane. Rudely inconvenient for most folks but far better than being actually killed.

Did you eliminate the opposition and win the encounter with one hit? Same-same.

 

[jefgorbach]

Unlikely. While its true throwing a grenade is often a viable option, this is an expensive one-shot idea with minimal results since by the time a group can feasibly obtain the portable hole and bag of holding, chances are they're facing either numerous minions (negating the effectiveness of a single 10ft kill-zone) and/or the point where dimensional anchor/etc have become almost mandatory to confront the single higher level solo (negating the planeshift effect).

 

[Ryujin]

Unlikely. While its true throwing a grenade is often a viable option, this is an expensive one-shot idea with minimal results since by the time a group can feasibly obtain the portable hole and bag of holding, chances are they're facing either numerous minions (negating the effectiveness of a single 10ft kill-zone) and/or the point where dimensional anchor/etc have become almost mandatory to confront the single higher level solo (negating the planeshift effect).

Hence the reason, presumably, why the OP is asking about the cost of tiny ones. Immaterial, at any rate, as it won't work in 4e.