eliminster

my engine in my 87 rx7 got fried when a buddy drove it and hit something that broke the oil line spilling all the oil out and starved the engine of oil. we fixed the line and can start the engine with some work and it shoots oil smelling smoke out of the exhaust and it also has oil coming out by the oil fill tube, i am guessing a back pressure thing from a blown oil seal. my question is how much will it cost to fix this
approximately, i am thinking it will cost around 3000 to have someone fix this since the engine housing was pinned and don't really want to get a new engine and do work on it. any help would be appreciated.