If you, or someone you know, has seen their hair getting thinner over the last few years then there are a couple of options to take.  First, you can do nothing and end up looking like Mr. McGoo or Telly Savalis.  Or you can make a choice to deal with the balding problems up front.  The are a few different methods that have proved successful and there are many different hair restoration cost factors that come into play when choosing which is the right treatment for your condition.
The main factor to consider is how much hair has actually fallen out.  If the hair is just getting thinner, and maybe the scalp skin is showing through, then you can often times get away with a medical over the counter product.  For example, Minoxidil is a drug which has been approved by the US FDA for the treatment of male pattern baldness.  It is applied topically twice a day and protects the hair follicles (roots) from attack by DHT which is the hormone responsible for the loss.  Often times you can see some hair growth, and a cessation of loss, within a month or two of its continued use.
If you have already lost most of your hair then the more radical treatment will be necessary.  Hair restoration surgery involves implanting hair follicles from a donor area at the back of the head into the balding spot.  Hair restoration surgery costs can easily run into the thousands of dollars but it really comes down to how much having a full head of hair is worth to you.  If you are tired of people making fun of your shiny head, especially if it is your idiot brother-in-law doing the teasing, then you will probably find a few thousand dollars well worth the price to pay to have your youthful hair back on your head again.  It would be sweet revenge.