Jeff Stewart submitted this

The truth behind cheaper imps:

It is NOT true that you can permanently set your imp-creating price to 150 gold. When you sacrfice an imp, the price of making an imp is decreased by 300 gold. Now, if you sacrifice enough imps, it will -appear- that your imp-price is 150 and goes no lower. Then, it will also -appear- that you creat imps and the price doesn't increase.

Well, as it turns out, seeing the price stay at 150 gold does NOT mean that your price is fixed. In actuality, the computer has made your imp price negative in memory but displays it as 150. Your imp price is still increasing, but you won't -see- it increase until you've made enough imps to make up for more than you sacrificed.

So don't get the wrong idea: imps are good and imps are necessary, but you can't put a permanent ceiling on their price.

Sound advice on making your library - just the right size!