Anything with a real (or fake IP) rating has a price 5 to 10 times that of a normal connector.
Previously I tried using the Aliexpress screw together inline type designed for outdoor LED lighting. They had an O ring seal but the contact quality was poor.
Has anyone found any panel mounted connectors that are well manufactured and don't cost a fortune? I can deal with fake IP ratings as long as the build quality is consistent and the contacts aren't rubbish.