At Korrin's Tower you can buy Senzu Products:
Small Senzu Pouch- 200 zeni (needed to carry Senzu Beans, Holds maxumum of 5)
Medium Senzu Pouch- 300 zeni (holds maximum of 10)
Large Senzu Pouch- 400 zeni (holds maximum of 15)
Senzu Bean 100 zeni (heals 50000 Hp and 5000 Ki, Can't be eaten during battle)
On Kami's Lookout you can train in the Hyperbolic Time Chamber for 6000 zeni. You get 2 weeks of Pl and Ki training in one day (70000 Pl and 28 Ki). You also can train with Kami for 700 zeni at 6000 Pl and 3 Ki per day for 6 days. At the end of training Kami will teach you a special move.
On Master Roshi's Island you can train with Master Roshi for 700 zeni. You train for 5 days at 7000 Pl per day and at the end he will teach you a special attack.
If you return one of Master Roshi's magazines to him he will reward you with a special item.
At Goku's training school you can train for 800 zeni. You first train for 4 days with apprentace 1 at 7000 Pl per day. Then you will train with apprentace 2 at 4 Ki per day for for days. Then Goku will teach you a special attack.