Primary Colors Set of Pyrex Mixing Bowls

I don't collect dishes, but this is one of those childhood memory things where finding one bowl develops into a quest to find the entire set. As a kid, I remember my mom having this set of Pyrex bowls. She actually still uses them to this day. A couple years ago, I saw the big, yellow one (#404) at the local flea market. The guy only wanted $2 for it. So I got it. After that, I found out that both of my sisters had a complete set. Well, then I wanted to complete my set. I found the green bowl (#403) at an antique store when I went home earlier this year to PA for a visit. Got a good deal on it. And then a few months ago, I found the blue one (#401) at an antique store about an hour from here. Got it for only $3 since it was marked 50% off. And a couple weeks ago, I finally found the red one (#402) at another antique store here. The dealer gave me a good deal on it, so I got it. For some reason, the red one is the hardest to find and the most expensive. Not sure why. This set, known as the Primary Colors set, was produced by Pyrex from 1945 to 1968. Based on information I've found about them, my blue, red, and green ones are all from the 40s (missing the number on the bottom, and the bottom is thicker). The yellow one is numbered and has the thinner bottom, so it's either from the 50s or 60s. Just one of those childhood things that I "had" to have.