I gotta wonder why GE changed the design from the R1 to the R2.  I like the pattern from the R1, which the R2 does not have.  The M250R2 has a very smooth design, and doesn't have the "engraved design" the M250R1 had.  What I'm wondering is why GE changed the exterior design at all.  I figure they could have made the interior as streamlined as it today, but kept the design of the M250R1.  Not saying I don't like the M250R2, but I definitely like the M250R1 exterior design a lot better than the M250R2, and I don't think I need to hold a vote as to who prefers the M400R2/M400A2 compared to the R3/A3.  I wish I knew who was smoking WHAT when they re-designed the M400, but that's another topic altogether.  So does anyone know why they changed the M250 design (and if you wanna give some input on why they changed the M400, go ahead), but I sure wish they had kept the exterior design of the M250R1.

With no real major changes, just subtle cosmetic things, my only guess is the new ones were cheaper to make. A few less lines and curves, easier mold to maintain, etc. And lighter. My '66 M250R is much heavier cast than my '79 250R1, and my '85 250R2 is the lightest of the bunch, ballasts notwithstanding....

@streetlight98 will be able to tell us soon enough the comparison between a 1985 M250R2 and a 2016 M250R2 

   Yeah the M-250R2 is significantly smaller than the M-250R1, so cost less to make I guess.

But some still charge $600+ to acquire one.  I wonder if they ever sell any of those.  Some unwitting person

Yeah the prices are crazy, though they're actually not a whole lot higher than they've always been. The cost of street lights has not gone up with inflation. Let's say a 100W MV M-250R1 cost $70 in 1977. It would cost $273.78 according to this inflation calculator. I guess they've managed to cut back costs enormously (by scaling back on amount of materials used, meaning smaller fixtures, thinner ballast coils, thinner castings, simpler designs, etc. and scaling back on quality in the process).