Ramirez, I'll mostly echo what the other guys said regarding the 740 you linked, I think you can find a nicer one than that with a £3k budget to be honest. With £5k you'ed get a really good one, but really I think that's a bit too much to pay for an E38 unless you really have a thing for them and want an E38 and nothing else. You certainly can purchase luxury cars for precious little money now, but as the others said, just be aware, they can be quite costly to run, if it's just routine stuff for a few years count yourself lucky, but you can be landed with some really quite nasty bills if you are unlucky. I would say the E38 740 is a better bet than an S class Merc to try on a low budget, an S-Class is more expensive in just about every way, even the older W140 (my personal favourite) will generally cost more to keep going than an E38.
It's worth looking at the older Jaguar XJ6/8 (X308) too, you can do very well for a £5k budget with those, and despite what people say about old Jags, the X308's are usually ok, they are from the period where Ford really improved the reliability a
lot over the older models. Of course, as always, do your research first and know what you are getting yourself into and potentially letting yourself in for.
Wow, just wow is all I can say, Derin you have had and have some stunning cars there, your attention to detail and apparent passion for your hobby is really quite amazing and gratifying to see. I hope you and people like you keep these beautiful older cars running for a very long time
I’ve wanted an R129 SL for a long time now, I looked at a few back in the summer of last year, didn’t really find anything I would actually buy for a price I was happy with though. Just spent the last few hours (holy crap it's 04:30) having a nosey around the ‘interwebs’ and I’ve found a few more promising examples of the SL320 (really good 500s seem to be like hens teeth) that might be worth a look, prices are down a tad too since it’s mid winter. Hohum, fiddle dee dee ...I really shouldn't

...but I do want one.