I think the intention was to have raids completed shortly after hardmode was released to have REAL raid items (earned via chambers of xeric) obtained. Hardmode will be the only mode with unflooded raid items via boss slayer when raids are released(wya). I understand the mode is less popular, but I doubt it's because of the boss shop. Perhaps give hardmode better drop rates? Something that pays for the "hard" aspect of the mode (like the 742) possibly?

PLEASE, DO NOT ADD RAID ITEMS TO BOSS SHOP.