Greg Zaal writes:
Greetings fellow blender heads!
I've just released a pack of five 16384x8192 HDRIs on the Blender Market for $3.95 - that's less than $1 each! I created them specifically for environment lighting in Cycles, so all you need to do is plug them in and you've got instant realistic lighting (without needing to fiddle with any nodes). And if you're not sure about buying them just yet, check out the free 2k samples here."
It's a teaser for what's coming later this year (more of them for a similar price), assuming you like these ones :)
They're also licensed as Creative Commons, so you're welcome to share them with friends!
The only reason I'm not giving them away for free is because I'd like to keep making them, and camera equipment is so darn expensive!
Anywho, I hope you find them useful!