Starter guide

Online Resale Store

Sophie's business at full size. Buy low on purpose, sell at volume.

$100 to $500 for inventory
Hard

This is Sophie's business at full size. Not selling a few things from your closet, and not flipping one thrift find at a time. This is buying low on purpose, at real volume, and selling to people all over the country. Estate sales, clearance racks, storage lot auctions, wholesale lots, garage sales at eight in the morning. Your edge is knowing what something is worth when the person selling it doesn't.

Start for free

Earn your way here

Start at idea 7, selling things around your house for free. Then idea 11, flipping a few thrift finds. Do not start at this one.

Here's the gate to pass before you spend a hundred dollars or more on inventory: sell twenty items successfully. Twenty. Not two. By item twenty you'll know your shipping costs, your platform's fees, which categories actually sell, and how long a listing usually sits before it moves. That knowledge is what protects the real money you're about to spend.

The plan

Your simple plan

  1. Pick one category and go deep. Vintage denim, or camera gear, or board games, or a specific brand of sneakers. Specialists spot deals generalists walk past.
  2. Know your numbers before you buy. Check the sold listings, not the asking prices. Sold prices are the only real information. Subtract fees and shipping, and only buy if the profit is still worth your effort.
  3. Buy where people are getting rid of things. Estate sales, storage auctions, clearance, and the last hour of a garage sale when the seller wants it gone.
  4. List every day, ship immediately. Volume is the whole game at this level, and fast shipping is what earns you the ratings that make future sales easy.

The parent and platform part

Most selling platforms require an adult account and an adult payment account, and that is not a rule to work around. A parent runs the account, and you run the business inside it. Agree up front on how the money is tracked and split, and keep honest records. Once you're earning real money, taxes become an actual thing, so talk that through with a parent early rather than in April.

The gear

What you need, and what you can skip

Most of your money is inventory. The rest is what makes shipping fast and cheap.

Get these
  • A shipping scale that reads to the ounce. Shop this
  • Poly mailers and boxes in two or three common sizes. Shop this
  • Bubble wrap or packing paper. Shop this
  • A thermal label printer once you're shipping regularly. Shop this
  • Clear storage bins with labels so you can find a sold item in ten seconds. Shop this
  • A phone tripod and a light for consistent listing photos. Shop this
Skip these for now
  • A storage unit. If your inventory outgrows a closet before you're profitable, buy less inventory.
  • Paid inventory software. A simple spreadsheet handles hundreds of items.
  • A wholesale pallet. Blind lots are how beginners lose money fast.

As an Amazon Associate I earn from qualifying purchases. We only list gear the guide actually calls for, and the skip list is there because most of it you do not need yet.

The lesson from the book

Sophie learned two things at this stage, and you need both. The first: you make your money when you buy, not when you sell. Every dollar of profit is decided at the moment you hand over the cash, not when the item finally sells. The second is the one that's harder to hear, and it's the one that mattered more to her in the end. Enough is its own kind of rich. This business can grow forever, and there's always another lot to buy. Decide what enough looks like for you before the buying becomes the point.

The full program

Ready to build the whole thing?

The full Young Founder kit walks you through everything Andre and Sophie learned: how to check real numbers before you buy, run volume without drowning, and know what you're building it all for. The book, the workbook, the videos, and more.

See what is inside the kit

Questions about this idea

What should a kid charge to walk a dog?

A kid walking dogs in their own neighborhood usually starts between $10 and $18 for a thirty minute walk. Professional walkers average about $21 for the same walk.

Read the answer

How much money does a kid need to start a business?

Less than almost anyone expects, and for a lot of these ideas the honest answer is nothing until somebody has already said yes to a price.

Read the answer

How does a kid find their first customer?

Ten people who already know them, one prepared sentence, and an easy way for each of them to say no.

Read the answer

What do I do when my kid wants to quit?

Find out whether this is not working or just not fun right now. Those look identical from outside and they need opposite responses.

Read the answer

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Young Founder

A program from Founder's Best Friend. Built for kids 8 to 18 who want something of their own.

Young Founder, 2026