Serif's Affinity Photo has just been updated and I think is on sale. It's less than PS elements and a perpetual license. I know a few people that rave about it and I'm thinking of taking advantage of the sale myself since they also have InDesign- and Illustrator-like programs as part of the sale.
I think OnOne also has there own photo editing software.
In any case, competition is good, though the past couple of years have been a lot of hype pushed by some of the other photo editing applications with little more than a few tweaks added and calling it a new version.
IMO, $10/month for Photoshop seems a bargain as it seems to be improving with each iteration and each new update. I wish Adobe offered the same rate for many of their other software apps.