Yeah, I worked out the costings but by the time you get all the bits and cut them to shape/size and built the thing, you could do it for maybe around $150-200, bear in mind you'd be building it for the first time, it would probably take all day, so $360 for the lot is very reasonable.
I'm happy with what we've got.
Schnitzel is our chicken that gives us the regular double yolkers and her biggest egg so far was 121 grams!!!! We think she had a sore bottom for a while after that! Due to her irregular egg sizes, she often has a few days break inbetween laying, whereas Parmigiana, is regular as clockwork, has laid every single day since we got them in September.
Also had quite a few in the high 110s. Here's a pic of the range of eggs we had at one point:
Considering that a supermarket 'Jumbo' egg is usually around 60-65g, all ours come out at around 60g or bigger, anything up in the 80s or above so far has been a double yolk!
PS Morbid fear of chickens is not entirely silly, they do attack my wife quite a bit when she's bringing food to them!!