I bought a little plastic box with eight partitions for AR$49 at Sodimac (US$3.10). This seems expensive and I thought maybe I could get an equivalent laser-cut for less. Mina was skeptical.
The dimensions of the box are about 130 mm × 110 mm × 25 mm.
There is one partition running in the 130 mm dimension and four partitions in the 110 mm dimensions, and there is a lid.
This works out to six partition edges and four face edges in the 130 mm dimension, thus 1300 mm, plus ten partition edges and four face edges in the 110 mm dimension, thus 1540 mm, plus 15 vertical edges of 25 mm, thus 375 mm; a total of 3215 mm.
My current laser-cutting cost model is that laser-cutting goes 24 mm per second and takes an extra 60 ms per vertex, and the cost is US$0.026 per second. Probably there would be about four vertices per vertical edge, for a total of about 60 vertices, a total of only 3600 ms, not significant in the overall cutting time. The 3215 mm would take 134 seconds, plus another 4 seconds of vertices, a cost of US$3.60. So it would work out to be pretty much the same cost, probably, or slightly more.
For larger boxes, I think the laser-cut MDF approach is definitely cheaper. Or if I can find someone who does cheaper MDF cutting.