Why the price of each share is so different for my retirement investment?

I have a target date retirement account with T Rowe Price.
I notice the price for each share is very different betwee 2040, 2030 and 2050.
For 2040 is like 18 dollar per share, but for 2050 is only 9 dollars and 2030 is like 13 dollars.
But the component of the funds are very similar to each other.
So, Why the 2040 is so expenensive in comparison to others?
If they are the same thing, why people buy 2040 instead of 2050 or 2030?

I don't understand why both 2040, 2030 and 2050 holds the same amount of S&P500, will have different in price.
So, why shouldn't I buy the cheapest?

If they each hold X billion dollars worth of stocks, the 2050 fund at $9 has twice the number of shares outstanding than the $18 2040 fund.
Price (net asset value per share) = value of holdings divided by number of shares.

They are different funds and have no relationship to each other. NAV (share price) is not the thing to focus on. Total return and costs (E.R.) are far more important to the investor.

Different funds have different price per share.

Each one of the funds have different mix of growth stocks, income stocks and bonds. The price should not even be part of the equation in selecting the fund. Pick the fund that matches your retirement date. If you pick the 2030 fund it will be less aggressive than the 2050 fund.

The price of each share is the combined price of each stock the fund invests in. They are never the same.

If they have different prices, there will be a different number of shares that you can purchase, in the end, it will be the same amount of dollars, unless one charges more or less management fees.

Beware of the funds named 2030, 2040, etc... they invest in other funds, and you may end up getting charge extra management fees.

The difference is that when you are young, you can afford to take risks that might make more profit, you have little to lose, but when you are older, and near retirement, you don't want to risk your big nest egg.