Hi, there are a few different possibilities I’d look into, based on this limited information:

First, I’d double check that you set up the ad campaign so that you’re paying by CPC (and not CPM), and that you’re looking at website clicks specifically and not clicks overall (the latter includes, likes, comments, etc). Are the ads in the same ad set? Are they running at the exact same time? Against the same target? Facebook ads are priced on a bidding basis, and the number of advertisers you’re competing against may vary.

Second, consider the amount of text on the image: If you have more text on the image, Facebook warns that the cost of your campaign can be higher.

Finally, take a look at your relevance score: This is a score on a scale of 1 to 10 for how relevant Facebook thinks your ad will be to the targeted audience, and your cost will be higher if relevance is lower.

Get in touch if you want to dig into the details of your results together and plan an effective strategy for your next campaign!