The thing is, it's pretty hard for an ordinary person to buy a share of a company. You usually need to be able to buy a large quantity of shares, pay for a trading account, try not to get ripped off with various fees, and deal with taxes.
This is FUD. You can easily buy one share if you want to. You don't pay to open a trading account. The fees are about as transparent as they could possibly be. And the taxes are not much more complicated than normal income taxes -- if you hold for less than a year your profits are taxed at the marginal rate and if you hold for longer than that you are taxed at the long term capital gains rate.
I'm not saying it's a good idea to buy one share of a $25 stock. It's not. But modern retail trading is accessible to pretty much anyone these days.
I would also add that many companies let you bypass fees and directly buy there stocks. Which can save you significant amounts of money if you want to say buy a few shares every paycheck.
Sorry I should have put a disclaimer that I was talking about trading in the US. I'm not as familiar with retail trading in the UK. In the US you will typically pay between $7 - $10 per trade for stocks (regardless of order size). These are the sorts of retail rates you see here:
Why can't I walk up to the stock market and buy a single share of Facebook?
If you have a membership on an exchange, the marginal cost of buying one share of FB would be the liquidity removal fee of $0.0030 (three tenths of a penny)†. But you don't have membership on any exchanges, so you have to buy your share through a third party, a stock broker.
Your broker is providing a service that has costs. Exchange connectivity is not free. Brokerage staff do not work for free. The website and backend technology are not free. Clearing is not free. Those costs have to be passed on.
There is a lot of healthy competition in the retail brokerage space. It's relatively easy to move your holdings from one brokerage to another, which suggests that competition has driven transaction fees to a level that allows brokers to cover their costs and provide a small profit.
Because the stock market is not a store. The price of a share of stock does not include the cost of running the market and its infrastructure.
If you want to invest without fees, find a no-fee mutual fund with low minimum investments. At the scale where $7-10 fees are onerous, I find it highly unlikely you have the money or sophistication to be investing in individual volatile securities.
This is FUD. You can easily buy one share if you want to. You don't pay to open a trading account. The fees are about as transparent as they could possibly be. And the taxes are not much more complicated than normal income taxes -- if you hold for less than a year your profits are taxed at the marginal rate and if you hold for longer than that you are taxed at the long term capital gains rate.
I'm not saying it's a good idea to buy one share of a $25 stock. It's not. But modern retail trading is accessible to pretty much anyone these days.