photocontest.org
Trust is the whole issue in this category. Photographers are rightly suspicious of contests that quietly claim rights to their work, and the entry-fee-harvesting operations have made everyone cautious.
An address that looks institutional helps enormously with that, which is why competition organisers gravitate toward the .org in the first place. This is the exact term on the right extension.
The economics are real: entry fees, sponsorships, print sales, and a permanent supply of photographers looking for somewhere to submit. Magazines run contests, camera brands run them, conservation groups run them, and thousands of local clubs run them.
The name suits an individual competition, a platform hosting many, a deadlines and listings site, or an association setting standards for fair contest terms. That last one barely exists and probably should.
Singular, exact, no hyphen, and it names something photographers search for constantly.
Enquiries welcome.