You could charge more if you also decoupaged some sort of background, like an olde newspaper or some vintage-looking wallpaper, the put the pics over that. I would also not concentrate on even spacing of the pics and things, which just appears to be randomness, but to maybe group things in a corner with a small stamp or something off to the side or an opposite corner. Just saying. I would then charge $25-45.
Thanks for your input, when I made mirrors that had things grouped in the corner and they didn't sell at all!
I also sell ones with decopauged backgrounds but wanted to offer buyers an option of something less "busy". When I just made the heavy decopauged ones I'd get a lot of custom orders for simpler designs.
Not terribly clear what are refering to as "which just appears to be randomness", all all of the images are clearly related as they are all vacation items: travel guides, post cards, a snapshot with handwritten message etc.