If you need more Cthulhu in your collection, this Pay-What-You-Want Bundle of Holding might be a good chance to do so. You have to pay more than the average downloader to get the Bonus material, though! (Usually comes down to 12-14 US dollars.)
This time included: Trail of Cthulhu Player's Guide. It's not the full rulebook, but it *is* a good deal.