A freind of mine is Iranian, and he grew up around BMWs and MBs. Yeah, in the middle east, the cars dont last. Then again, with that much sand and dust and extreme tempurature flucuations between days and nights, what does last a long time?
As for oil changes, they are very simple to do on the e36. The oil filter is right on top and the drain plug can be reached without jacking up the car. To do it yourself, you're looking at 5-7ish for the filter and 10-20 depending on what oil you use. For regular oil and filter it costs 27 at my garage where they reset the lights, but unless Im having other work done, I do it myself.
Other things you may have to do include what are called "Inspections." Inspection 1s basically give the car a good lookover and change most fluids. An Inspection 2 does everything as the former, plus changes filters, plugs, ect. Average cost of Inspection 2 is 350-500. Inspection 1s range from 200-400, all of this depends on your garage. The Inspection cycles are carried out around 15-25k miles, depending on how you drive.
<span style='color:gray'><span style='font-family:Courier'>1995 e36 3 Series RIP
1999 e46 3 Series BURN IN HELL
2000 MR-S Roadster= Current</span></span>