The local Retailer / Installer can quote all the prices they want, they do not mean a thing as in the end it is Dish Network who the service is through not the local retailer.
In other words the local retailer could be quoting you old lower prices or just making things up to get your install, they dont mean a thing and they wont hold up as the Contract is through Dish not the local guy, you must pay the rate that Dish says.
Everyone in the country has to pay the same monthly rate for the new customer promo, the best deal you can hope for is free up front things like Free Starzs for 3 months and extra credit off the install or referal credits and no up front fees to lease SD DVRs or non DVR HD receivers.