I know at first glance the cost of native app development may seem high but when you compare the cost of deploying an app with more traditional methods of content delivery they are really on par. A lot of final programs that are designed and printed cost clients in the vicinity of $5-10K for design and print alone (volume and event dependent of course). Native app costs sit squarely in the middle of this. When you also factor in that apps, if launched early enough, present a more targeted communication tool than email marketing you are also saving hundreds, if not thousands of dollars in your marketing efforts.
In addition to these costs savings native event apps also provide a lot of opportunities for your clients to generate show revenue via the app through sponsorship and advertising sales. Securing an overall app sponsors alone should more than cover the cost of deployment. You can also add silver level sponsors and sell advertising space to exhibitors and local accommodation, restaurants etc. I have written an article on this topic which may help you see things differently.
In general most of our clients generate between $15-35K of additional revenue via the app by utilising the tools mentioned above so there is really no reason why people should shy away on price. I often find, when I did a little deeper, that it is not price but lack of knowledge as to how well the app will work for them that is the main objection. Price is just an easy out.