@ArpanaR
Yes, you definitely can, not just could. In the days of the Holy Roman Empire, buying titles was pretty much the norm. Rich merchants bought noble titles all the time. It may not come with land, but it was possible to buy land and noble titles at the same time. French nobilities could even be 'bought' by paying money to be adopted.
Today, you can be a Scottish 'lord' by paying for 1m square land, which means nothing in reality because the Scots didn't have the same concept as English lords. Scottish 'lord' (laird) basically refers to a landowner and not knights. You won't get a coat of arms with this title, but Ai-chan is sure there are ways to get a coat of arms legally.
If you are not hung up on West European titles such as Baron, Count and the like, you can also buy a Malaysian noble title (Dato, which is a sweeping title for a range of noble titles). It rarely comes with land and it's not a medieval noble title, but it is a legal and respected noble title and you can attach it in front of your name legally. How to get it? By performing certain deeds and applying for the title. You can throw money at a charity the sultan (or his queen) is supporting or turn a village into a bustling trade center or own a port and it will most likely grant a noble title. It will be yours alone and can't be inherited by your children, but you can keep it for as long as you live.