status/DamageStatus.cs
using System;
using System.Collections.Generic;
using System.Linq;
using Sandbox;

[Status( 7, 0, 1f, 0, false )]
public class DamageStatus : Status
{
	public DamageStatus()
	{
		Title = "Bigger Bullets";
		IconPath = "textures/icons/bigger_bullets.png";
	}

	public override void Init( Player player )
	{
		base.Init( player );
	}

	public override void Refresh()
	{
		Description = GetDescription( Level );

		Player.Modify( this, PlayerStat.BulletDamage, GetDamageMultForLevel( Level ), ModifierType.Mult );
		Player.Modify( this, PlayerStat.BulletSpeed, GetSpeedMultForLevel( Level ), ModifierType.Mult );
	}

	public override string GetDescription( int newLevel )
	{
		return string.Format( "Increase bullet damage by {0}% and decrease bullet speed by {1}%", GetDamagePercentForLevel( Level ), GetSpeedPercentForLevel( Level ) );
	}

	public override string GetUpgradeDescription( int newLevel )
	{
		return newLevel > 1 ? string.Format( "Increase bullet damage by {0}%→{1}% and decrease bullet speed by {2}%→{3}%", GetDamagePercentForLevel( newLevel - 1 ), GetDamagePercentForLevel( newLevel ), GetSpeedPercentForLevel( newLevel - 1 ), GetSpeedPercentForLevel( newLevel ) ) : GetDescription( newLevel );
	}

	public float GetDamageMultForLevel( int level )
	{
		return 1f + 0.1f * level + (level == 7 ? 0.1f : 0f);
	}

	public float GetDamagePercentForLevel( int level )
	{
		return 10 * level + (level == 7 ? 10 : 0);
	}

	public float GetSpeedMultForLevel( int level )
	{
		return 1f - 0.1f * level;
	}

	public float GetSpeedPercentForLevel( int level )
	{
		return 10 * level;
	}
}