You can almost always buy any gun cheaper on line, but if you can, buy from a local gun shop (not the big box sports stores). You may find the prices sometimes are close when everything is totaled up.
The other reason is local follow up support. If you have a problem with an online purchase....good luck.
If you purchase online you will still need a shop (FFL) to send it to anyways. Maybe this will be the same shop you can purchase from and continue doing business for a long time.