Actual cost, new replacement cost (where applicable), or market value? Each would go into a different bracket for me.
Personally, I'd be a lot more interested in the ratio of gun collection cost to savings (e.g. money put into 401(k), IRAs, etc). In my case it's about 1:3 ... over my life I've spent $1 on guns for each $3 banked to a retirement account. On the market value side the ratio is closer to 1:2.5 ... I've been a better gun investor (which really means I've lucked out on some good deals over the years) than mutual fund investor.