A three-tab, six-step decision protocol. Run this every time before you bid, buy, or commit. Skip it and you will overpay.
i.
The Core Formula
First Principles
value = mintage × condition × demand × authenticity
ii.
The Six-Step Protocol
1
PCGS CoinFacts — Population & Auction Records
Search the coin. Note total population, population at the specific grade you're considering, and the most recent auction prices realized. A coin with population 3 at MS-67 is fundamentally different from population 800.
Look up mintage by year and mintmark. Check VarietyPlus for known errors or doubled dies that materially affect value. Compare NGC's price guide against PCGS's — the gap between the two is your real range.
Search the exact coin and grade. Read the last five-to-ten sales over twelve to twenty-four months. This is what the coin actually sold for, not what a price guide claims it should cost. Trend up, flat, or down?
Same search at GC. Lower buyer's premium means prices skew slightly closer to true market. Use as a second data point against Heritage and average the two. Two sources beats one, every time.
Plug the cert number into PCGS or NGC verification. Confirm the coin in the photograph matches the grade, year, and any variety on record. Counterfeit slabs exist. This step is non-negotiable.
Set your maximum at the lower end of recent sales minus ten to fifteen percent. If asking exceeds recent comparables, pass. If below, bid. If unsure, wait — coins are not scarce, the next one will come.
Population data supports asking price relative to grade
Pass Immediately
Walk away
Raw coin priced as if graded
Description includes cleaned, polished, AU details, problem
"BU" with no third-party grading
Stock photo reused across multiple listings
No return policy on a $100+ coin
Seller below 500 feedback or sells across unrelated categories
Asking 30%+ above recent sales without explanation
Cert won't verify, or photo doesn't match certified grade
Two minutes of research will save you a thousand dollars over a year. Skip it and the market will find every dollar you didn't protect.House Rule · No Exceptions