Let me say this about that: To truly become a collector and not just an accumulator, you need to have decoy collections to through SWMBO off. You have to begin by having her accompany you whilst looking over stuff that you have you're eye one (but all the while, watching what she looks at). Then you start buying a few of those items, keeping them out for her to admire, while all the time, somewhere hidden away, the true treasures accumulate.
For me, it is plumb bobs. Wife loves them, and when in my shop, admires them. Gives me the ability to keep adding saws! Also, accumulate smaller items like stones. You can have a dozen dirty old stones piled in a corner that the fairer sex just ignore because of the oil, gooey mess (helps to have spider webs).
But the absolute best way to accumulate things is to never, and I mean never, comment about the every growing closet of shoes she buys. Just ignore brand names like Kate Spade, Nine West or Michael Kors, that appear on all sorts of goods in your house - because you know, that down in the shop, you;ve pulled a fast one in sneaking the $7.00 dollar stone into the shop AND SHE DOESN'T EVEN KNOW! (right).
If the thunder don't get you, the lightning will.