The case studies don't have to be in-depth, and you could really limit it to 1 page, just showing off what you did and the result. If possible show a study for each package you have and how get a quote from the client on how much money they saved using your pricing model compared to other quotes they may have received.
Regardless, I still think the best approach is to drive the potential customer to contact you. By just hiding the prices and having them reach out to you, it gives you an opportunity to close the sale personally. Whereas, if they come to your site, see the packages/prices, are confused or think the pricing is to high, they will leave without you ever getting a chance to close the sale.
One last item I thought of on your packages. You and I both know the packages listed are for mobile applications, but I would clarify on that to the website visitor. If they are looking for a 1-3 page website, the price is going to be an immediate turnoff, and the way the site looks now it is not clear those prices are for mobile development, IMO.
