Foreclosures are listed on the MLS like any other property. Banks and the GSE's want fair market value like anyone else does. In fact, in the Phoenix market, Fannie Mae has consistently listed their properties above market over the last several years, dangling the easier to qualify for, low down payment Homepath mortgage as a carrot to attract buyers.
Writing a low offer on a short sale used to work occasionally, but lenders know they are operating in a seller's market today, and are more insistent on getting market value.
I can't imagine owning rentals in a fee heavy, high tax, tenant friendly state such as New Jersey. I'm not a masochist and I prefer positive cash flow.