Water filtration systems are like computer printers....they discount the machine to get your ink business! That is where the moneys. Same for filter cartridges!
In my PERSONAL opinion, I don't like whole house chlorine filters. You can get growth going on inside the pipes and valves.
A shower-mounted chlorine filter is a good unit. MOST people are fine without it , but some folks are sensitive to the chlorine so go for it. In terms of drinking water, a simple taste-and-odor unit at the kitchen sink will take care of that.