Player-to-player transactions

1. Player Trading vs Player Selling (Virtual Economy Gamification Tips)
2. Virtual Wealth vs Real Wealth (Virtual Economy Gamification Tips)
3. Barter System vs Trading System (Virtual Economy Gamification Tips)
4. Game Economy vs Virtual Economy (Gamification Achievement Systems Tips)
5. Game Taxation vs Real Taxation (Virtual Economy Gamification Tips)
6. Item Rarity vs Item Value (Virtual Economy Gamification Tips)
7. Farming vs Grinding (Virtual Economy Gamification Tips)
8. Tradable vs Sellable (Virtual Economy Gamification Tips)
9. Player Economy vs Developer Economy (Virtual Economy Gamification Tips)
10. Virtual Budget vs Game Budget (Virtual Economy Gamification Tips)