It's not terrible for in vitro studies, but that would be a stretch for in vivo studies at a CRO, especially for oncology, where lots of studies require tumor grafts. It's not my area, but I think those mice can run $1000 and up per animal. The cheap, more common strains are ~$25 each. I haven't looked at the papers they're trying to replicate, but in my lab, it's not unusual to have 60 mice in a study, so you can see how just getting animals into your facility can be expensive.