So let's examine a setup with three cages, with two parent mice having a litter of 6 every 45 days. So every 45 days we have a new batch of 90-day-old mice, and they cost $135 or $23 each. Add a couple more dollars to sustain the ancestor mice, add enough inefficiencies to double the cost, that's still only $50 per mouse. Rearing costs aren't even going to hit 1% of $17000.
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.
