Brick-wise, it looks like the whole thing is just round studs in varying colours stuck on a black 48*48 sheet (it might actually be 16 12*12 plates) that then gets mounted in a frame. If you're up for making your own, you could pretty easily find yourself a sprite art generator to turn your desired picture into a 48*48 sprite (or whatever dimensions you want, really), then order the studs on their own in the colours you need, put it on a background sheet (cut to size if needed), and mount it in a dollar store frame. It'd be a bit of work to organize the whole thing, but quite doable and probably cheaper than $120.