coinbase discrepancy

Okay, so here i sit watching and waiting and learning the best i can for days. I decide today the price starts going up on the bitcoin again and looks like it may actually be done falling so i take my little bit of money to invest and check things out. 1st EVER investment of any kind that does not involve me putting my hands on tangible merchandise. So i go to Coinbase to do it. It is a very very small amount. I put in the amount of cash to convert into bitcoin in hopes that when i can then actually get a bittrex account it will go up and my tiny chunk will have grown a little bit. Finally i pull the trigger and hit buy. All the while i am watching bitcoin go up and down on https://bitcointicker.co/ and see the price set at 14XXX, i look back at my coinbase purchase and note that i bought my share at 14,723.09 and i look back at the ticker to see that in fact the price for bitcoin according to that, has never crossed 14400.00 as of yet for the day. so now i am wondering??? is that ticker completely wrong in its pricing or is coinbase actually charging me more (so i get less) for my purchase. I then go back to coinbase and set up another purchase for the same amount and take it all the way up to the conformation stage just short of an actual purchase. then i immediately look at the ticker again and see the price selling is again at least 300$ short of the price i was going to pay coinbase. I did this 5 times and each time it was right around the $300.00 range of shot at the current market price. Is this a normal kinda thing, is it the ticker i am using telling me wrong ###'s I am confused now