To echo old, price per share between companies has no meaning.
Hence why we look to metrics like earnings per share or (share) price to sales ratio or many others.
To wit:
Company A earns $1 billion. 1 billion shares exist. Earnings per share is $1.
Company B earns $1 billion. 500 million shares exist. Earnings per share is $2.
All else equal, if A's share price is $25, B's will be $50. B's shares are worth 2x since its earnings per share is 2x.
Share price movement becomes a function of expected earnings changes in the future, more or less. Add on general market drift, political changes, management changes, competition, tax changes, and the general fact the future is hard to predict, and you have a difficult task.