You can order DirecTV equipment from third party vendors such as Solid Signal, which will then be shipped to you and which you can install. You would then need to call DirecTV to activate the unit. Keep in mind any equipment "purchased" in this manner will still be considered as leased by DirecTV, and activating it will still incur a 2 year service agreement.
If you have in fact moved another receiver to the location in question and confirmed that it is a working location, then this should work for you. If there is only one connection, then you may or may not be able to put a DVR at that location and have use of both tuners (with a single coax, you can only get dual tuner use with SWM technology - shannon01 indicated how you can check for that).
If DirecTV is offering you a DVR or receiver at no cost, but charging $50 to install, that is a better deal than ordering from a third party vendor (where a receiver will be about $100 and a DVR about $200).
If you try to get a receiver or DVR from an auction site or anyplace other than an authorized dealer, be very careful. Get the receiver ID number (RID) and verify with DirecTV that the unit is owned, and that if you buy it you will be able to activate it on your account. You will not be able to activate any leased receiver you buy from someone.
Just to be perfectly clear. Press the dash button as previously posted. Does the resulting message indicate SWM connected? If not, your system is not capable of handling another DVR (non SWM systems have a four tuner limit, and you already have four) and you will in fact require a new SWM dish professionally installed.