IMHO
I doubt the memory will be comparable. Most likely the only things usable in a new PC build are the case, power supply (if high enough wattage), and drives. The MB, CPU and memory are usually changed out together and the video card because it too is probably slow compared to today's standard. One reason I always just handed down my older computers and built a new one. I also look at the break point from a cost/performance point of view. Better to buy a decent PC now and then later replace it with another decent one down the road than to spend big bucks on a cutting edge one now (unless what you are running software wise needs that extra 20-30% performance). For gaming there is not much difference between an i5 and an i7. So unless your doing video editing you can save about $100 US there. Not sure about over the pond pricing.