To unlock Priscilla for the brothel, keep going to the Magic Shop owner then choose the second option. (That Inn Refresh Strategy). If you’ve done this about 8 times, you should have all the easy CG sets by now (Brothel, Weapon Shop, Magic Shop, Skirt Flip Guy) You might have to rotate the orders in which shop you go to as well, so just keep doing it until you get something new. I recommend buying all the items from each shop too – cause you might as well with all that money; it’ll help you a lot with the upcoming enemies.
After buying all those weapons and armour. Talk to the armour guy this time instead of the weapon guy, and choose the last option. This should trigger something where he’ll give you a bunch of strong free items. (Probably for being a loyal customer)
You might notice that you have these ‘love heart’ armour as well. I think I unlocked it from getting damaged really badly from strong monsters.