Never considered using one. I don't even use one for AI except perhaps for lora training.
I might mention that an older NVIDIA 1070 ti can be had for as little as $85 US on ebay.
https://www.ebay.com/b/NVIDIA-GeForce-GTX-1070-Ti-Graphics-Video-Cards/27386/bn_110676216
Even that card would be sufficient for most Iray renders.
As for render farms, most cost $ and of course there's the privacy issue.
commercial paid: https://irendering.net/price/
Volunteer, free: https://www.sheepit-renderfarm.com/home
commercial paid: https://render.st/plans-pricing/
Folks could also try stable diffusion with img to img and see what they get.
Anyway, lots of ways to go. Let us know what you settle on and how it does.