IF you dont need the altitude or lifting performance of the 530 the 500E may be just as practical (more so from a fuel burn perspective). The 505 is designed as a private helicopter where as the 500 is was designed to go to war. My thoughts as someone that has operated both:
500/530
+ Coolest helicopter on earth
+ A true pilots machine
+ Robust airframe, very easy to fly even if you are un-current
- No baggage space (unless you add a pod)
-Limited fuel range (especially the 530 with the C30)
-Old technology engine and avionics, Engine is easier to hot start
-Really a 4 seat helicopter, 5 is tight.
- Great view and visibility in the front, passenger experience in the back is not very nice.
505
+Modern engine with FADEC
+Modern avionics
+5 proper seats
+Good fuel range
+good baggage locker
+2 blades makes easy hangaring
-Not as nice to fly as the 500, although he hydraulics are good
-Ugly
-C of G issues if you are doing lots of people movements (i.e. flying empty one leg and full the other)
In my opinion I would buy the 500 if you want to look and sound cool, otherwise its hard to go past the 505 as a private operator. There are a few calendar issues with the engine and TT straps, so if your utilisation is super low the 500 may end up cheaper to run. But depending on the age of the machine, most 500's seem to cost similar to a squirrel to operate from what I can tell.
From a safety perspective the 500 is a really crashworthy airframe, and you cant mast bump it. But it lacks the crashworthy seats of the 505 and if the engine goes quiet the 505 glides a lot better.
Try both and see what you like. I wouldn't discount the EC120 as that is probably the nicest 5 seat to operate as a private owner if you ignore the running costs.. I used to operate a 505 along side an EC120 on charter and I would take the 120 every time.
Just my 2c