No one should enter into a dropshipping venture with no cash; it's a set up for failure the first time you get an unsatisfied customer (or just a trivial grief player who likes to cause problems, scam artists etc.) You cannot count your customers' money as your money until they have their order in hand and have left you feedback (if on eBay or another platform with feedback) because the unfortunate fact is, up until that moment it is trivially easy for the customer to get a refund, without even consulting you.
Not having any liquid capital will burn up any business, of any size, in any industry. You need to plan ahead, have at least a few weeks' worth of anticipated order volume in cash or credit available, so that you can keep things running smoothly and take any issues with individual customers as they come, rather than letting one derail your whole operation.
Frank