Great project! Travel companies usually dive straight into the latest res system when they often don't need to with the beauty of web services. Sounds like you both saved and made them a packet!
What I find more amazing is that they'd lived with a booking process that just didn't convert well for years and no one had ever questioned it. They just spent more and more cash trying to raise traffic and traffic quality. Small investment in the UX and they're in the money... (this is a big household name holiday company in the UK).
Not saved but made them more. As head of ecommerce for a travel company I suggested small ux tweaks to their checkout process and they got a 25% conversion uplift. Worth something ridiculous like £5m per year. Needless to say I still got a poxy bonus which is why I now freelance :-)