It may be the largest wholesaler directory, but Worldwide Brands isn't the only source of certified wholesalers and drop shippers on the Internet - there are many more and some are cheaper, at least in the short term.
Worldwide Brands is the oldest directory of certified wholesalers, drop shippers and manufacturers. It was founded in Florida in 1999 and is still based there to this day. With more than 16 million products from about 9,000 suppliers, Worldwide Brands is the largest directory - but with a membership fee of $299 it's also the most expensive.
One of the alternatives - and potentially the cheapest - is Salehoo. Salehoo is a directory of certified wholesalers and drop shippers as well, but it has fewer products on offer - only about 2.5 million as of 2018. Salehoo does have about the same number of suppliers though, so you may find more products by contacting them directly. Salehoo is much cheaper than Worldwide Brands - membership costs only $67.
Another alternative to Worldwide Brands is Doba, but although it's cheaper at first, Doba adds up to be the most expensive at $29 a month. It's really easy to use though - unlike Worldwide Brands, Doba is a fully integrated system for getting goods drop shipped to your customers.