Karen Cherepak was hoping for a spring break getaway to Mazatlan. She thought she found a great deal on line and clicked "book now" for final pricing.

"As soon as I clicked on to confirm the $539 price, it jumped to $1,100 some dollars," she said.

She tried again. This time she found a WestJet Vacation on www.itravel2000.com for $539 plus $124 in taxes. When she clicked to book, the price jumped to $1,419 per person plus $130 in taxes.

We tried it too. This time on Flight Centre and found the same thing: from the time we found the price and clicked to book. This time it was a $192 difference.

"I would just like to see proper pricing," Cherepack said.

"It's a very solid complaint, I don't know the numbers, but we get hundreds every year, I haven't heard of one being resolved," Bruce Cran of the Consumers Association of Canada said.

He advises you to check the final price before you click "accept."

"If you press the button at the wrong time you maybe spend a hundred dollars you didn't want to spend," he said.

Both iTravel2000.com and WestJet Vacations told us the price you see on the website is a "snapshot" cached in their system, but it's not up to date when prices are changing quickly because of higher demand.

Other travel websites have disclaimers saying the pricing is for comparison purposes only, which means the exact price may not be known until everything is confirmed.

"Oh it's ridiculous because it's totally time consuming. Time consuming to the point where I've almost given up," Cherepack said.

You are more likely to experience this problem when booking popular travel times like spring break, or Christmas or when there is a really good seat sale. So check the final price closely it may have already changed.

With a report from CTV British Columbia's Chris Olsen