At $2,999, the Sigma 500mm f/5.6 Sport isn’t cheap, but it’s $250 less than Nikon’s new 400mm f4.5 lens, and $600 cheaper than the Nikkor 500mm f/5.6 PF, but then the Sigma lens is unfortunately not available on Nikon Z mount. I compare it to Nikon’s lenses because they’re really the closest thing to the Sigma 500mm f/5.6 Sport.
However, on the L mount and Sony E-mount platforms, there’s no prime lens like it for even close to $3000. Sony does sell 400mm and 600mm primes, but they are both well over $11,000. It is worth noting that the Sony version can be adapted to Nikon mirrorless cameras fairly easily, though the adapters themselves are kind of pricey.
For L-mount, this is pretty much your only option in a super telephoto prime, but as with E-mount, it’s also worth considering a super telephoto zoom lens, of which there are several excellent options. Sigma’s own 150-600mm and 60-600mm sports lenses are the key competition here, both of which are also in Sigma’s “Sports” line. The 150-600mm is the cheaper of the two, and both fall within the $1500-$2000 price range, so are more affordable than the Sigma 500mm f/5.6 Sport. However, while they’re excellent lenses, and their focal ranges are more versatile, they don’t deliver the extremely high level of image quality, or relatively bright aperture, of the 500mm f/5.6.