Pvc will hold up because its very strong, but the cage wont be sturdy because its so flexible, It wont matter how much time you put into building it, its gonna look like the leaning cham cage of pizza.
I think also that it has more to do with what the insects in the wild are eating, not the types of insects.I add crushed egg shells into my got load mix, this alows me to dust less. but I still dust at least once a week with my females and twice when they are gravid.
another though, where did you get you chams, breeder? pet store? most times when you buy a pair at a pet store ( they often give you a deal for buying a pair) they dont bother to tell you they are brother and sister, they more than likely beet around the bush about it, and this could resault in...
Gut load
I don’t think I saw anything about egg shells for gut loading in any of these posts so I'd like to recommend it, just crush them up and add to your gut load mix, this is especially great for gravid female but over all its just a great source of natural calcium.:D
The key thing you said was " I'm not an expert", Make your self an expert before buying any Cham or you will end up disapointed and regretfull. There Is so much information out there so read every webpage you can find until you cant find any more cham info and them buy your pet. and you wont...