I've been playing a new free game on my cell phone recently called Castle Clash. I've also got my roommate addicted to it It took my quite a while to find the hero upgrade costs so here they are.
When you first get a Hero they are level 1 and can reach level 20. A Hero can have 9 stars, and presumably reach level 180. You get your heroes experience by running dungeons and battling other players (the way that costs gold).
When a Hero maxes out it's level it can be upgraded. When upgraded it will gain a star, raises the Hero's max level by 20, and increases the Hero's stats a little.
| Star | Gold price | Hero Badge price | "Flames" requirement |
Max. Level |
|---|---|---|---|---|
| 1 | N/A | N/A | N/A | 20 |
| 2 | 10,000 | 1,000 | 10 | 40 |
| 3 | 30,000 | 3,000 | 50 | 60 |
| 4 | 100,000 | 10,000 | 75 | 80 |
| 5 | 200,000 | 20,000 | 105 | 100 |
| 6 | 300,000 | 30,000 | 135 | 120 |
| 7 | 140 | |||
| 8 | 160 | |||
| 9 | 180 |
^ Conquering Dungeon rooms gives you "flames."