To be honest, would a spreadsheet not be a good use for this? There are FOSS asset trackers, but a simple .ods with a pictures column might serve you well.
Are there additional features/conveniences you are looking for?
I wonder if something like a picture or video is sufficient to inventory quantities and general cost, such as clothes. The number of t-shirts I have changed over time, but a week worth of Carhartt adds up
I was thinking of doing that, but I don't think it would handle attachments gracefully. I also don't want to inflate it to a 100gb document with all of the attachments.