Shopping

General advices

 * Take all the stuff you can find on the road (see secrets and collectibles)
 * Don't rush for stuff. You can survive with bad stuff you can wait to find better for free. Simon started the devil pass dungeon in Iron armor (of course your first moves are a rush for Lustplate)
 * Don't buy potions. You can find many and you have skills to heal your group. Even sleeping can do a "Revive" or remove poison. I used 3 antidotes and 2 revival potions so far.
 * Sell what is 1 category lower of your gear (if everybody wears steel armor sell Iron ones)
 * Keep stuff that you can't buy. I have kept Simon starting gear even if it's bad because it's unique. Also true for Slave Collars and Slave Pins.
 * Keep most accessories (at least one item of each) just in case they can be useful (for example against a monster without special powers).
 * Keep 1 Iron shield (since it doesn't have an AGI penalty) for Simon just in case

Forest

 * Nothing to buy there

Merchant Camp

 * Consider buying 1 Steel Sword and 1 Steel Dagger before the fight in the hall. Only one dagger because Aka will have her custom blade later.
 * The Potion seller is a crook, don't buy anything there

Stineford
A place for your first shopping spree. Remember to do some missions when you're low on cash (for example raiding the slaver's house)

Thief in Bar

 * 4 Thief Pins before the mine or killing bandits (only place you can buy them) before the mine, the Spider dungeon and many other venomous animals.
 * Buy nothing else here, he's a crook

Jewelry Store

 * A Mage Hat for Robin before going to the Academy

Armor Shop

 * A Steel Shield for Simon and a Tower Shield for Hilstara, help a lot before the Spider dungeon
 * Ore for Aka

Weapon Shop

 * A place where you can buy Warrior Pins but no real need to do so. Spare your money
 * Manufacturing Dagger for Aka

Magic Item Shop

 * 2 Mage Rings before fighting in sewers (you can find one free in sewers and use a slave pin for your fourth member Yarra)
 * Enchantment for Aka's Dagger

Bunny Shop

 * Only Place where you can buy a Healer's Ribbon but no need to do so.

Red Cape Inn

 * You can buy all the alcohols here. No usage for now but I bought one of each just in case.

Whores (optional)

 * 500 Sx for the noble one (to have Yarra at 100)
 * 100 Sx for the succubus in brothel

Succubus Tower

 * A butplug for Yarra (great for fighting) and handcuffs for Qum Dumpe (increase drastically her utility in fight, not for the damage but for the lust stun)
 * Only place where you can buy handcuffs so far

Yhilin
In fact no shopping in chapter one there. Wait until Chapter 2

Outskirt Shops

 * Nothing to buy there but it's the only place where you can sell stuff

Premium steel

 * 2 Dwarven Helmets (so there's 3 dwarven helmets Simon, Hilstara and Robin), A Drudge sword for Simon (may be useless but since we don't know where he will be send I have stuffed him, you can do the version 11 with only steel but it's your last chance to equip him)

Magic Shop

 * if you have invested in the magic shop buy 1 Fire staff, 1 Ice staff and 1 Thunder staff. If not buy two of these staffs (for Robin and Altina). Carina will stay with shining staff.
 * Personally since I want all my 9 party members to be immune to silence, I also buy 3 Mage Rings there (for the moment you can swap but I consider this like cheating). It's one more than needed because for Yarra I like to be able to chose between Mage Pin or Slave Pin

Succubus Village

 * Some succubus stuff but nothing needed

Megail Path
Equip Hilstara and Carina with Mage Pins and Varia with Slave Pin. They have plenty of HP and can withstand some round under poison but they need their skills to fight. Varia is in steel.

You will need 20 000 Sx for buying the bounty hunter office so don't spend all your money.

Premium steel
Bounty Hunter Office
 * A drudge Sword for Varia.
 * If you win a Full plate Armor during the Orc attack use it for Hilstara and give steel Armor to Varia. If not buy steel Armor for Varia
 * You can buy Thief's Pin there but no need to do so for the moment. At least the price is at 1000 there
 * 20 000 Sx for buying the office

With all this at the end I was around 3000 Sx at the end.