Please define "expensive". If it's a consumer app, hacking a wordpress template should only cost about ~$500.00 or hacking the sample projects from Parse.com can cost about ~$500.00-$1,000.

If it's a enterprise play, then you should be able to close $50k-$2mil for a paid project engagement from an enterprise client just by having a good powerpoint deck and an awesome sales pitch.

If neither options works, then you probably need to refine the idea more.