It's tough. The way I usually go about things is to get 2 or 3 18/19 year olds with good potential and a good trainer. Focus on training them for a while. After a few seasons you should be able to sell for a nice profit or keep them, then start the process over. That will give you a nice chunk of cash, or if you keep them, you'll have some good starters. If you keep them and can afford a decent veteran or two (without spending too much money), that should be enough to keep you from relegating while you work on training the next group.