Vintage Pyrex in primary colors. I look for these while out junking and that includes thrift stores. I refuse to pay over $5 for any 1 piece. I have MAYBE $40 in all my pieces (I have more, but a couple are being used and the others have patterns <~ not my fave). I love finding these - Hoss went to a yard sale with hubby 2 weeks ago and he is the one that found my latest 2 pieces (a lil blue bowl and a red bowl). As you can see, I have multiples...in case 1 happens to break I have a backup.
Still on the lookout for the illusive green bowl (now, I need 2).