For each manufacturer investigation, the fee is about 20$, for some interested manufacturers, this will incur on-site investigation, so the price I think is reasonable. Native Chinese speaker, good at negotiating.
Especially for the T-shirt, I have a friend who has started up a company doing this business, seeking for collaboration if you really will do this business. for other business, if it's related electronics, I will be more interested to be involved, Thanks, and waiting for your response