[archaeolept]

well, even a minimally equiped banelord will be
20 death + 10 astral +10 water and that's w/out lightning or fire resist.

for 50 astrals you get an archangel + 6 angels, each holy, armed w/ flambeaus which are vicious against demons and moderately tough undead, flying, and w/ some innate fire and lightning resist (only 50%, but more commonly needed than the banelord's poison and cold immunity). The archangel has F3 and H4, both nice and useful in their own right.

If you're running a blessing, and fighting abyssia or mictlan for instance, you might rather want to go for them...

I bought a bunch as marignon once, running an F9 S9 dual bless. Also as Jot fighting ermor, running an F4 W9 bless.