How to use basic data to decide what to buy next

Making Smarter Reselling Decisions Using Simple Data

Whether you’re new to reselling or looking to scale up, knowing what to buy next can make or break your profits. Instead of guessing, you can use basic data—right from your own sales and inventory—to guide your next purchases. This guide breaks down simple, actionable steps for beginners who want to grow their reselling business with confidence.

1. Start With a Central Inventory System

The first step to making data-driven buying decisions is to keep your inventory organized and up-to-date. Many beginner resellers juggle spreadsheets, notebooks, or even try to remember everything—which quickly leads to mistakes, missed sales, and duplicate purchases. Instead, set up a central inventory system that tracks:

• What items you have (with descriptions, categories, and images)

• Where each item is listed (e.g., eBay, Facebook Marketplace, Poshmark)

• How many are in stock

• Cost to acquire each item

• Sale price and fees

Tools like Gavelbase make this process easy and help you sync inventory across multiple selling platforms automatically. If you’re not ready for a specialized tool, a simple spreadsheet (like Google Sheets) works to start—just be diligent in updating it after every sale or new listing.

2. Assign Basic Team Roles (Even If You’re Solo)

Even if you’re running your reselling business alone, defining roles helps keep your workflow organized and efficient. If you have a small team or family members helping, clear roles prevent confusion and errors. Common roles include:

• Sourcing: Finds new inventory to buy

• Listing: Creates online listings with photos and descriptions

• Shipping: Packs and ships sold items

• Bookkeeping: Tracks sales, expenses, and profits

Assign tasks based on strengths and availability. If you’re solo, batch tasks—such as dedicating a day for sourcing and another for listing—to stay focused.

3. Track Sales, Fees, and Profits

The most useful data for deciding what to buy next is your own sales history. Every time you make a sale, record:

• What sold

• Where it sold

• How much it sold for

• Associated fees (platform, payment processing, shipping)

• Cost of goods sold (COGS)

By tracking this information, you can quickly see which items sell fastest, which platforms perform best, and which categories are most profitable. Many resellers are surprised to find their assumptions don’t match the actual data—so let numbers, not guesswork, guide your next sourcing trip.

How to Analyze Your Data

• Sort your sales by category or item type. Which items sold out quickly?

• Calculate your average profit per item. Are some categories consistently more profitable?

• Check return or complaint rates. Are certain items more trouble than they’re worth?

• Compare platforms. Does one marketplace outperform the others for certain types of items?

4. Decide What to Buy Next—With Confidence

Use your tracked data to create a simple “buy list” for your next sourcing trip. Look for patterns such as:

• Fast-selling categories (e.g., electronics, branded apparel, collectibles)

• High-profit items (items with highest margin after fees and shipping)

• Low-effort wins (items that are easy to list, ship, and rarely returned)

For example, if you notice used video games sell quicker and with higher profit than clothing, focus your next purchases there. If kitchen gadgets sell well on Facebook Marketplace but not eBay, prioritize listing similar items on the right platform.

Pro Tip: Watch the Trends

Keep an eye on seasonal trends or local demand—back-to-school supplies, holiday decorations, or sporting goods can see spikes in certain months. You can use free tools like Google Trends to spot rising categories, but your own sales data is often the most reliable guide.

5. Handle Shipping and Pickup Cleanly

Efficient fulfillment is just as important as sourcing. Track each item’s shipping or pickup status in your inventory system. For every sale, record:

• Buyer’s shipping address or pickup details

• Date shipped or picked up

• Tracking number (if shipped)

• Status (pending, in transit, delivered, or picked up)

Clear records help you resolve disputes, answer buyer questions quickly, and avoid costly mistakes like double-selling or misplacing items.

Many inventory tools—including Gavelbase—allow you to sync order status and automate updates, but you can also use color coding or filters in your spreadsheet to stay organized.

6. Keep It Simple, Review Regularly

Remember: the goal is to make data work for you, not to create extra work. Set aside 15–30 minutes each week to review your sales and inventory. Ask yourself:

• What’s selling fastest?

• Where are your highest profits?

• What’s sitting unsold for weeks?

• Are there recurring issues with certain items or platforms?

Use this quick review to adjust your buying strategy and avoid repeating mistakes. Over time, you’ll get better at predicting what’s worth buying—and what to skip.

Useful Resources

• Gavelbase – All-in-one inventory, listing, and sales tracking for resellers

• Google Sheets – Free spreadsheet tool for beginners

• Intro to Data Analysis – Free course to boost your data skills

• Google Trends – See what’s trending in your target categories

• ShipStation – Shipping management for small businesses

By using basic data from your own operations, you can make smarter, more profitable buying decisions—without guesswork or overwhelm. Start small, stay consistent, and let your numbers guide your next move.