Probably. But really, if you're spending $50,000 on an experiment, you're probably more interested in getting mice that are really what it says on the label, than in saving a few bucks and possibly shooting your experiment and/or career in the nuts.

Pretty much anything 'lab grade' is going to be expensive. The lab I worked in ordered a lab grade laser for optogenetics experiments, and that cost something like $18k. Presumably that gets you a very precise, stable wavelength.