If you expect to be using lots of coils in the future, look for an eBay seller with the Make An Offer option in their ad. Some sellers like to haggle so you can get a much better deal by buying the coils in bulk. I’ve bought several lots of twenty at a time and it worked out to less than $15 CDN ($11.75 USD) each with free shipping. The packaging isn’t the greatest but they all arrived undamaged and are working.
On second thought, it might have been $10 each I paid for them.
