The point of heroic fantasy gaming is to have or do stuff you cannot do in ‘real’ life - this includes being rich.

Would you like to be rich for a while? Really? What would you buy? Well my friend, D&D is your chance! You already figured out you can ‘pimp out’ your character. Good start. What else could you possibly buy? Good news: you have a long list of options - my apologies in advance for this wall-o-font.

Heroic Shopping List / Cool &/or Interesting Fantasy Stuff:

• ‘Healing Potions’ … was just the beginning!: A healing potion is a ‘common’ magic item. Buy more of them. There are lists of these. These can be really fun (‘add to your campaign’) and rarely mess up the game (‘useless in combat’). My favourite is the indestructible enchantment - they never wear out and they make amazing tools.
• Even BETTER Gear: ‘Silvered’ blades vs. werewolves, adamantine arms and armour, multiple non-magical spell book copies, more spells copied from fellow wizards, light mithril barding for your mount (or a mount with more hit points / a lucky constitution roll).
• Services - The help of sentient beings &/or people’s support: This is what money buys in our ‘real’ world - the help of others. Exotic chefs, spas, carriage chauffeur, herald announcer, musicians and more. Most gamers balk at any kind of sexual service for hire (despite the success of most hollywood epic-fantasy shows). You could instead buy a good reputation - or destroy the reputation of anyone you dislike. Also, nearly anything you wanted to do during downtime… you can hire someone to do it for you. Check Xanathar’s rules and see what you wanted to do on your next vacation and get it done. ‘Time is money’ they say in business - now’s your chance to buy your time back.
• Buy long-lasting spells: Usually folks buy Continual Flame, Arcane Lock or Magic Mouth. There are lists of spellsyou might purchase. Clever merchants use Spell Storing devices so you can have a familiar or steed - or even a Greater Steed - forever / until it is killed.
• Weaponized Service of Sentient Beings: older versions of D&D had hirelings and men-at-arms. Want ten well-armoured archers? Someone to carry your lamp? Hire them. If you have too much money, equip them with arms (‘longbows are expensive’) and armour (‘plate mail is horribly expensive’). They will last really well until that Red dragon breathes on them.
• Real Estate: tired of being a murderhobo? Buy a home and call it your ‘base’. Ever wanted to own a palace or castle? Do you even know what the difference is? You can also get exotic and fun locations: a lighthouse, a house in-above a covered bridge, a apartment hidden behind a waterfall, a treehouse within an Awakened tree (‘it goes with you if you treat it nice’), own part of the attic in a famous play-stadium (enjoy Shakespeare or gladiatorial tournaments? - permanent seating arrangements). How about a keep on the borderlands? The options are endless. Real estate means you don’t just play part of the adventure, you own it.
• Any business you ever wanted! You always wanted to own a pub? How about a guild? Every class has a group or organization they can run (thieves guild, wizard’s academy, mercenary association, templar guardians, travelling rock band, etc.). Run that business - any smart DM can and will compliment this with adventures.
• Mounts & Transport: Carriages can carry ALL your treasure, hence the name. Share the load! Start with a solid dog or donkey and move up. Also, flying mounts (more on this below).
• Exotic beasts, magical beings & more!: Flying mounts are just the beginning! Most players’ characters have ‘ethics’ and avoid slavery, but anything with intelligence of 4 or less is a pet or beast of burden. Start with buying a few dozen attack dogs with mithril plate armour-barding - find out what your DM does with your twenty attacks per round.
• Buy valuable stuff: Adorn anything with jewellery - carriage, armour, swords, your favourite spoon - you name it. Silks for clothing, curtains or your dogs. Finally emblazon your shield as your Family Shield, complete with guilding. Plant a garden with overpriced / hard to manage flowers. Sculptures with extensive artistic clout and history. Gold toilet. Overpriced yet ancient alcoholic beverages. All these things are what the Stupidly Rich buy - you can too, but economically, in your Heroic Fantasy.
• Go Full-On Nickolas Cage: Buy weird, wild & wicked stuff with no apparent value. Gargantuan Dragon skull. Jacuzzi tub - formerly owned by an Elder Brain. Map of that Vanished Kingdom. Silk tapestry depicting Ye Ancient Lost Battle of Yore. Statue of Lesser (petrified?) Hero. The Nevertouched Sword - apparently cursed (?) so no one dares to touch it. Name it, you bid for it at the auction and now it is yours.
• Make Magic Items: This is probably the BEST use of your money, but please talk to your DM on this one. Allowing your character to build Your Precious can wreck your game. Theoretically it is possible to build any magic item (even artifacts & relics with the support of your god - looking at YOU, clerics and paladins). The Dungeon Master can easily prevent you from getting any recipe-plan-desgin or make sure you cannot find the special components needed for your item’s construction.

You can imagine that this is a short list. Everything has a price and quite often that ‘price’ can be paid in money. If so, your hard-earned gold is your very best friend (not your dog / don't believe everything you hear).