What kind of engineering? I have a CS/EE (computer science/electrical engineering) degree and the majority of the programs I used didn't really need a large amount of power to run...but then again, I was mostly just coding.
But, if you're going into civil engineering then yeah, it would be nice to have a nice system at home so you don't have to spend all your time at the library. Just off the cuff here is a list of what would be a good system to have and at a decent price:
CPU: Intel e8500 CPU/AMD X4 940 or higher
GPU: Nvidia 2xx/ATI 4xxx or higher
RAM: >= 4GB DDR3
PSU: >= 700w
Mobo: depends on what CPU you get/how long you want to wait until upgrade
Case: Mid size tower
HDD: I'd recommend getting a small sized SSD for your OS, then a secondary HDD to save all your files on.
Anything less than those parts (performance wise) and you'll start to notice a considerable difference in render times/fluidity of the software. Price wise you're looking at no more than ~$700 and some of them you can catch on sale, like the e8500 and RAM (sign up for Newegg's newsletter).
Also, with some of the parts (like the e8500/GPU) I would expect for you to OC them. I've taken an e8500 and gone from 3GHz (stock) to 4.1GHz with full load @ 50c. You don't need to OC RAM, as you only really see a difference in performance when running benchmarks.
Anyway, I hope this helps!