The present research examines the effect of the costliness of an information source on children's selective learning. In three experiments (total N = 112), 4‐ to 7‐year‐olds were given the opportunity to acquire and endorse information from one of two sources. One source, a computer, was described as always accurate; the other source, a puppet, had a history of either accuracy or inaccuracy. For some children, learning from the computer required giving away stickers. The costliness of the computer clue reduced children's use of this source across all experiments, but its effect on children's use of the puppet varied based on the puppet's accuracy and the type of information learned. Children's trust in the puppet was above chance regardless of the cost of the computer when they were learning generalizable semantic information and the puppet had a history of accuracy. When the puppet was inaccurate or when children learned episodic information, the costliness of the computer significantly increased children's trust in the puppet. Hence, attaching a cost to a preferred knowledge source reduces children's selectivity and increases their trust in sources that they would not otherwise see as desirable. Copyright © 2013 John Wiley & Sons, Ltd.