Never commit capital to a Bitcoin mining deal before running the actual ROI numbers. Use our free calculator with your specific hardware specs, hosting cost, and BTC price. If the person selling you the deal won't give you exact numbers to plug in, that is itself a red flag.
The Three Ways Mining Deals Go Wrong
In our experience reviewing hundreds of mining deals, bad outcomes fall into three categories. Understanding these categories helps you know where to focus your due diligence.
1. Overpriced Hardware
The hardware markup problem is endemic in retail mining. An Antminer S21 Pro retails directly from Bitmain for approximately $3,800. Through a broker, "turnkey mining package," or casual reseller, the same machine might be quoted at $5,500-7,000. That $1,700-3,200 markup comes entirely out of your ROI — it extends your payback period by weeks or months and sometimes makes an otherwise viable deal unviable.
The fix: always price-check hardware independently before accepting a quote. Compare against Bitmain.com for new machines and eBay completed sales for used hardware. Refuse any deal where hardware is priced more than 15% above what you can verify as current market value.
2. Uncompetitive Hosting
Hosting costs above $0.08/kWh effective (or $300/month flat fee for a single S21 Pro) significantly compress margins. At $350/month hosting vs $225/month, you lose $125/month = $1,500/year per machine. At 5 machines, that is $7,500/year the person next to you is making that you are not.
The fix: compare any hosting quote against our verified hosting comparison. Always calculate the effective $/kWh from flat-fee quotes to compare on equal terms.
3. Contractual Traps
Contract issues are the most dangerous because they can result in losing your hardware entirely, not just underperforming on ROI. Common contractual traps include: no exit clause, zero liability for equipment loss or damage, vague or no uptime guarantee, hosting contracts that let the provider terminate without returning your machine, and auto-renewal clauses that trap you in another term.
The fix: read every contract in full before signing. If you are not comfortable reviewing contracts, hire a lawyer for one hour — it is cheap compared to the risk. See our full hosting red flags guide for a complete checklist.
The Due Diligence Framework
Step 1: Verify Hardware Pricing
- Get the exact make and model of the machine being offered
- Check Bitmain.com and MicroBT.com for current new pricing
- Check eBay completed sales for used pricing of that specific model
- If the quoted price is more than 15% above market, negotiate or walk away
Step 2: Verify Hardware Specs
- Confirm the exact hashrate and power draw vs manufacturer specs
- For used hardware, request a video of the machine running with pool stats showing actual hashrate
- Verify the serial number if possible
Step 3: Calculate the Actual ROI
- Plug exact specs into our ROI calculator
- Use the hosting cost exactly as quoted — do not use "ballpark" numbers
- Run scenarios at flat difficulty, +20% difficulty, and -30% BTC price
- Calculate hardware payback period in each scenario
- Compare hosting cost against market alternatives on our hosting comparison
Step 4: Verify the Hosting Provider
- Get the physical address of the facility
- Search "[provider name] review" and "[provider name] scam"
- Ask for 2-3 customer references and contact them
- Confirm all pricing in writing including all fees
- Read the contract — especially exit terms, liability, and uptime guarantees
Step 5: Get a Second Opinion
Before committing capital, get a second set of eyes on the deal. Our free deal review provides an honest Pass / Pass with Conditions / Avoid assessment within 48 hours. For larger commitments ($10k+), our $97 Mining Deal Audit provides a complete written analysis of your specific situation.
Common Scams to Avoid Completely
Cloud mining contracts: Companies that sell "cloud mining" contracts — where you pay for hashrate without owning any hardware — have an overwhelming history of fraud or failure. The economics rarely make sense, and you have no recourse if the company disappears. Avoid cloud mining entirely.
Guaranteed returns: No legitimate mining operation can guarantee returns — mining revenue depends on BTC price and difficulty, both of which fluctuate continuously. Any deal that promises specific monthly returns is either misleading or fraudulent.
Turnkey packages from unknown sellers: "Buy this package and earn $X/month" offers from unverified sellers are the most common source of mining losses. Always decompose the deal into its components — what is the hardware? What is the hosting? What do each cost separately? If it cannot be decomposed, walk away.
If You Think You Have a Bad Deal
Submit the details through our free deal review. We will give you an honest assessment of whether it is a good deal, what concerns we see, and what you should do next — within 48 hours, at no cost.