Well, I went to the horse's mouth and asked Bird 1) how much, and 2)
might I drop in ...

Hello Jeff,
The cost for calibration on 2500w slug is base on Frequency Bands
The cost 2500H is $100 the cost for 2500A; B; C; D; E AND J is
$200
Regarding walk in, no we do not Calibrate walk-in basis.

Best regards,

Not unreasonable, I think, for commercial concerns, given the time it
likely takes to do this and the investment they have made in
professional-grade equipment. A bit steep for me for casual, amateur
use though.

.... at least they were nice.

73,
Jeff