I haven't seen that many k plated 325i cabs. I think they are quite rare. Most of the K plated cabs I've seen are 4 cylinder (318i) but well spec'd.
It looks like it's been looked after but if it's rusty and not economical to save, dependant on the details of the spec it's worth £500-£750. If it's worth saving, you could end up with a bodyshop bill of £500-£1500 for metal and paint.
All parts you need to fix this up are available here and some of us are more welcoming than others, which is being addressed.
Others will chip in but remember this is all my opinion.
Good Luck, look at the wiki buying guide, it should be immensely helpful.
