Rookie mistake. Never, ever, not one time, add up everything. Especially don't leave a digital footprint that spouses may find and blow it for everyone else.
This is how you play it. I got a sweet deal on this barrel. $159 marked down from $400. I had most of the other parts just sitting around. A couple more bucks for some pins and springs. That's all I can think of... I built this sweet rifle for like $300, tops.
Your wife does it too when she gets a shipment of makeup and stuff. You really believe that sample was only $10? It's how the game of married life is played.
Reminds of the joke (or not!) that goes, "I hope that when I die, my wife doesn't sell my... fishing rods / tools / guns / knives / guitars / bikes / etc... for what I told her I paid for them!"