Reducing Bushings in header

I am trying to decide on running dual 2" risers out of my boiler, to a 3" equalizer, to create a Hartford loop, or whether a dual 2" riser/2" equalizer is enough.  

Is it bad to use a reducing bushing between my risers and my equalizer/header? The local supply houses don't stock either a 3"x2" reducing 90 or a 3"x3"x2" reducing tee, I was quoted $60 per 3x2 90 and $67 per 3x3x2 tee. That seems expensive, given I would need 4 tees and 1 90, that adds $350 to my header budget alone! Plus the $80 to cut and thread one piece of 18"x3" pipe to go between the 2 risers. I understand big pipe is not cheap, but that seems like a lot of dough. A regular, malleable iron, 2" 90 is $5....a 3" is $20. Reducing bushings are $10. Given the extra cost of the 3", its kind of hard to justify.

Everyones thoughts?