Face it. If you're a collector your brain is wired differently from the average "joe". You may see things as functional, mechanical, historical or even dare I say it...a work of ART! Feel fortunate that your interests are in quality goods like Single Shot Rifles and Double Guns instead of beer cans and matchbook covers...at least you have taste.
Also feel confident that if SS's and Dbls are your only addictions, such a limitation can be controlled, at least to the extent of your bank account.
Some of us have multiple afflictions: Gunning Accessories; Vintage Hunting Photos; Shell Bags, Cases, Cleaning Rods, Boxes, etc; Decoys (which can match the cost of a vintage car)... need I continue? So the concept of too much stuff, too little time, and way too little money is a constant strain on the psyche.
Go buy something...you'll feel better...for a little while anyway.
