I'd much rather have an E30 over an E36. E36 has good performance, but doesn't feel like it has the build quality the E30 did.
My commute is 45 miles one way, and I did the same math as above when trying to decide on my commuter. I started with an E30 325e (32mpg), lots of torque and very fun to drive. I then wanted a 40+mpg car and narrowed it down to either a Civic or VW Tdi; with a price cap of about $2000 that I chose to allow a ROI of 18months or less. Chose the diesel Jetta, averaged around 46mpg for the year I drove it and it paid for itself in less than a year. After owning/driving BMW's for 15+ years it was difficult for me driving the Jetta everday, so I decided I'd rather spend 2 hours/day in something that handled/braked/accelerated/more comfortable than the beater VW. I ended up buying a Mini this winter, and the only time I don't feel like I'm in a BMW now is when I try to power out of a corner (I still miss rear wheel drive), but 37MPG and 'BMW'ness have made my commute so much nicer.

You need to determine what your budget is and what kind of daily driving you do to figure out what car you should get, if you should get one. If you want something super reliable that you don't want to do any work on, look at Toyota pickups.

Sell the X5 and buy something that is both cheaper to maintain and easier at the pumps. Don't do the two car thing at your age.

Don't take this the wrong way..... did you not look into what costs are associated with running/maintaining such a vehicle? My X has been my daily driver since I was your age, and I'm now 26. It hasnt been an inexpensive vehicle by any means (before we even get to the mods)....but all the issues associated with these vehicles have all been well documented; and would have turned up with a simple search. The $120 fill-ups (right now it's $5.60/ us gal) are by no means economical.....but then again the X was never intended to be an "economical" choice, nor did I purchase it with the expectation.

i think im just going to go with the 318is e30 till i get around to getting a 4.8is because i have a 4.4

I agree, do the math. At 19, I would think, unless other ride is a Vespa, the insurance cost alone would burn any gas savings. I think you should also deduct from the X cost the worth of the fun factor to you, put it in $$$ I think you said you don't like your job--I would be looking for one I like better that paid for the current pain at the pump. Take it from experience the favorite ride in the garage, even if a cherry, rare collector grade vehicle should be driven and enjoyed or sold.

if anything, my insurance would go down because i wouldnt have an x5 dont you agree?

I would think if you can't budget $2000 a year for maintenance and $4 a gallon gas, then an X5 may not be the right car for where you are currently. Wait until you can truly afford to properly maintain these somewhat fragile cars.

Oops, I thought you were talking in addition to rather than in place of. That being the case you have great suggestions already it is just a different math problem that will help you make a decision that is good for you.

You have your whole life ahead of younto have nice cars and whatever but you just need to do what's best for your situation right now

I use to have it all but after a wife and 2 kids things change

I use my 2001 A4 as my daily/work/raining outside car, x5 pulls out of the garage when its sunny and afterwork/weekends ride. I dont like putting miles on my 4.8is but i wish i could drive it all the time without racking up miles lol. Am also 19.

Audi local doesnt get great mileage at all.. 19ish, summer with a/c on even worse, hwy i pull out 26- almost 29 depending if always driving/any traffic/speed.

Edit: also dont make the mistake of thinking a smaller engined car or smal engine with turbo will net you better mileage, depending on driving if local/hwy,
The bigger engined v6 may be alot better option even if lets say split of 50/50 driving..

The v6 esp with ac running will end up netting you most likely better mileage local then a smaller 4 or turbo 4 because you need to rev it out more, yeah on hwy you will get a little less with v6 then 4, but it will even out cause of better local, and hwy 4 will get lets say 28mpg vs 6 26mpg.