Nah, Gunblade is a piece of crap. Not worth paying 2.4k for an extra nuker when a sheen gives you a bigger bang for half the price, for instance.
That said, Lich is also not that great either. It's another defense-delaying item that pushes you into the role of glassassin Kaiser. Yeah, it has MR, but it ain't anything compared to a negatron item and it necessitates a deathcap or at least 1.6k dunked into even more AP to make it worthwhile. Much better to double-dip defense + AP that you can use reliably and get some sort of xtra trick instead of forcing you to go into melee. Not even the Mace of Spades bug is worth being so glassy.
--
Sburbopolis, Homestuck RPG: http://www.gamefaqs.com/boards/8-gamefaqs-contests/60981373