Awesome! Another E24 pops up in the islands. FYI, these E24s are really not a collectors item yet. Do you know if you have a US model or European model? What color is your car? The M635csi/M6 models would be more of the collector types. Standard 635csi are not so rare these days. Although a very well kept 635csi can still be desireable to enthusiast. Suggest you check out Bimmerforums.com in the E24 section to get a lot more information and help with your new E24 venture. Lots of helpful folks there willing to help and give good advice and honest direction. Post your pics there and get ready for a rundown on what you have in your possession. Are you thinking of keeping it or selling it?
Pending the condition of your 1984 635csi, it will range from $1000 and up. For increased valuation above $2K, first and foremost, the car has to be rust free with very good to excellent paint conditions. Most folks who know these cars will look at overall condition of exterior paint, leather interiors, crack free dash, solid headliner, mileage on the car (less than 90K is good), all A/C - Electrical systems and exhaust/cooling systems operational. Unfortunately, Automatic versions are least desireable, but everyone is different in what they are looking for. The engines themselves cost $$$ to be well maintained, but usually not as large an expense as the other things that plague these old cars. A brand new M30 engine can be found for $1500. Compared to outfitting new interiors ($3K+), body work and new paint ($5K+), new dash ($2K), new headliner ($1K), new exhaust and headers ($2.5K)
Looking forward to seeing pics of your acquired E24.