[rgejman]

In practice you need to maintain large colonies in order to reliably have enough mice for experiments. Also you need to keep gender in mind because females can be housed together but males cannot and generally experiments are conducted in either one gender or the other.

So, let's say you need 20 female mice for an experiment (e.g. 4 groups of 5). That means that you need to have >40 offspring in order to get enough female offspring. That's at least 7 breeding pairs (assuming you're not harem breeding) and you've got to maintain them for 6-8 weeks until you can use them. That's >$1,000 in breeding costs before you get to the actual experiments.

[Dylan16807]

But even after all that you're still at ">$50" per mouse. This isn't the part that makes a mouse cost 5 figures.