Amazon is the obvious option that comes to mind, using their FBA setup Link hidden: Login to view
So an option like that is going to save you labour and storage space issues, but the payoff is that, of course, you have the service fees to then add to the price of the item. Now if you can source in bulk, use the FBA and remain competitive, while still making an acceptable margin on your items, then that probably is a pretty solid option for you to consider.
In this business, the more cash you have, the more you can buy and that in turn secures you the best price you can afford (at the time). It doesn't always provide you with the best price possible, that always comes down to the pricing structure of the supplier.
For example, spend 5K and get 25% discount. Spend $7,500 and get 27% discount. Spend 10K and get 30% discount and so on.
Not everyone structures it in such a way, but you always watch out for that MOQ trap that many fall into. MOQ is only the MINIMUM order they will accept, that doesn't always guarantee you the BEST price possible. So always confirm pricing structures when dealing with wholesale purchasing because that type of trap can really catch a lot of people out by spending what they have on the MOQ amount, only to then find that after spending all their cash on stock, while other resellers are spending more, buying cheaper and squeezing them out of the market.
Of course, it's not all about the cash flow either. the more you do yourself, as in self-storage, shipping and so on, the more you also then save.
So the end game equation is, money spent + money saved + margin made - costs = X