woo 1cc Hitogata Happa on Normal! I chose to buy a couple of Lovers and a Fortuner instead of cheaper dolls, so no TLB, but not too bad for my first shot on Normal.
Also, if you're looking for a doll to Solo Voyage, use Earl. On Easy, prices go down to about mid 200 gems per Earl, so it's easily possible to get triple digits in terms of lives. Only things you need to watch out for is low damage output without Daath Whisper and enemies from behind (which Rallyman's Beam can't track).