Hi Penny,
THE cheapest hotel to stay in MVD is the Hotel Tres Cruces. It is like staying in a college dorm room with lots of hot water. The neighborhood is so-so, and fine during the day but you may want to stay in after 10PM. The Hotel is located 1 block from the main bus station, and so it is easy to get anywhere from there to anywhere in the country, let alone in MVD. I would contact them and see if you can negotiate say a two week stay ro something for cheaper than their nightly rate. If not, and you are absolutely certain you want to go there, I will set you up with my real estat agaent who has rented many apartments. Only thing is he does not like to waste his time on people who are uncertain if they are coming, or what to spend, etc.