You often see advertisements for really cheap domain name prices. But there is always a catch.
Almost always, the special price is only for the first year.
The idea is an old advertising trick. Put a big discount on the first year price. make the profit on the next year.
The price for year 2 is always higher than the special offer.
The tactic is about capturing market share. Those who offer really cheap domains are prepared to lose money on the first year to get you as a customer.
In some countries, selling below cost to gain market share is considered an unfair trade practice, particularly if you are a dominant player in the market.
It is also disadvantageous to the consumer. You get hooked in by the cheap price for the first year, and then find that deal does not last. Over time the consumer often ends up paying more,