Like our good friend, I also invested in some stitch index books recently. There was a sale and I thought Why Not. (I'd gotten at a book thrift shop one of the card index things but was not as happy with it. Gave it to a young friend, instead.)
These few books have a lifetime of inspiration in them. The Lace and Eyelets was a real favorite and the Cables book was AMAZING. But I have to admit they were all worth the expense. I don't think the Interweave book sale is still on but if so these are worthy of consideration!