Buying a domain name is a simple task, but you should be carefull where you buy it, because some of the registrars are using their franchize very nastily.
In the First days of the Internet there were not many Domain names registrars. Actually 2 or 3 registrars were controling the domain name market completely. One of them is "Network Solutions" that still exist but no longer one of the top 3.
I purchased my first 2 domains through "Network Solutions" 13 years ago. For 13 years I have been renewing the domain name every year for… $10 (which is the same cost as a new domain name a reasonable sum) 6 months ago i started receiving notification about renewing my domain names and I was surprised to find that renewing the domain for 1 year costs $ 34 (yes a new domain still cost $10 !)
however if I will renew the domain name for 100 years (who the hell is going to live so long ?) it will cost me $ 10 a year (but i will have to pay $ 1000 for this).
The alternative is to change registrar i.e. to take the domain name you purchased and move to another service… this isn't simple as it sound, first it costs around $ 30-50 but mainly because some registrars will not allow you to do this. So you are stuck and in most cases you will pay the ransom (because thats what it is a ransom as your domain name was hijacked/kidnapped) Complaining to the authorities (ICANN) get you nowhere (you will get an appology "Sorry we do not deal with this" ).
You can try the American consumer organization, but if you are not American you will not get an answer, and "Network Solutions" is American.
So what do you do ?
Think carefully where you register your domain name !!