If you have kontakt take a look at spitfire labs, loads of cheap little kontakt packs, must be something there for you to enjoy. http://www.spitfireaudio.com/shop/ranges/spitfire-labs/
Buy Transfuser https://www.audiodeluxe.com/products/air-transfuser-2 It really cool plugin! And Xpand https://www.audiodeluxe.com/products/virtual-instruments/air-xpand2 Not the best, but 1$ only
Or you could go to your local dealer for some herb and smoke that if that helps you in being creative. After all plugins and sample packs are pretty useless without creativity
There is some really, really huge sales on this site, thanks for sharing! Definitely will buy Xpand2 for example, not in love with the product but I know it can sound really interesting and 1$ instead of 99$, definitely worth it.
I COMPLETELY agree with what @ArticStorm said, I know they cost around $50, which is more then you said you wanted to spend, but Valhalla products are worth SO much more then what they cost... and are my go to reverbs for pretty much everything. Great design, great sound, amazing thoughtful developer.... big thumbs up from me... or if you are looking for Kontakt libraries, check out Sound Dust... really clever and interesting inspiring stuff...