csytal can be a tricky thing they come in all kind of size, configuration, paralell or series.
oscullators perhaps is what you're refering to as 2.4 ghz
yes i know, it only coat $.50 if you buy in a batch and you gatta pay $10 to $15 for a replacement in R/C

but you have to get the proper frenquency to match your reciever and tx.
i worked in electronic manufacture for years and years. Had crystal failed of course.
And there's crystal all over the warehouse or i can ask for free samples. it would
take me all day anyways to call around looking for the exact crystal i need.

But I'll never take a chance of putting $300 in the air just to save $10.