Sometimes a gene just doesn't feel "worth it" for X price, but would be a must-buy at a lower one. This is especially true for gem genes where there's a real dollar value assigned to them. 2700g is roughly $25, which is potentially two hours of work. Is that worth it? Personal value assessment there. Treasure genes are a lot of the time easier to "justify" because treasure is so readily available on the site.

(This is a general observation btw, not specifically my own opinion. I don't really have a horse in this race one way or the other.)