+1 for “you won’t hear the difference w/ a step down transformer,” assuming you have a transformer rated for the needs of the equipment at hand. If we think about it, every device plugs into the wall and converts the wall voltage to the voltages needed in the audio circuit. No mystery here on how this works.
If there’s a difference, I think it’s much smaller than the difference in Accuphase vs. not Accuphase within your budget.
To give you a sense of price (few hundred $) from another thread on operating Japanese gear in the US:
Here’s another suggestion: send it to George and have them convert the unit to 110v, and skip the transformer altogether. I suspect all the hardware is there and it’s merely a matter of using the appropriate taps on the power transformer, but it’s likely George would know and could answer whether this is a viable option over the phone.