Can anyone recommend a candler that works well, especially on blue and dark eggs, for under $25? I mostly want one because my 11 year old son is really into incubating eggs, and just loves when we candle them. We use our own eggs, and they are mostly just a farmyard variety, so it's not like I really have any stake in my hatch rate...I just want something that I can use with my son to enjoy seeing the growth process inside the egg. We have been using a small, led flashlight, and it works ok, but I know he would just be amazed if we could see into the egg better. Thanks!