UPDATE
At last decision made and purchased. My criteria was mainly cost - mm range and amount of usage and optical stablisation. So just ordered a Panasonic 100-300mm f4.0-5.6 II Lumix G Vario Lens. This cost £479 against £1500 elmarit . I could buy 3 of the one I bought, makes one think
Had a serious look at this the 50-200 amd 200-400 elmarit versions and have to be honest I cannot see how they justify the cost . OK what about the used ones then? yet again did a lot of searching on all three and It appears that dust was present in all that I looked at from different companies. Now to my mind I asked myself why were they being sold
second hand? there nust be a good reason, which gave me doubts.
So being a bit fussy with my gear I decide not to go for someone elses throw outs also the cost of around £1000 for used I thought was a bit steep and the risk of getting a bd one diidn't justify getiing one.
So the version I have just bought should be ok for birds-animals- butterflies etc and those that are a bit further away. As I said I looked at vertually every youtube video there is to get others viewpoints.
Now have wait and see how good it actually is when it comes. The boss says I have to get rid of some of my Nikon gear as well to help pay for the purchase so that will be the next step on here to see if anyone is interested.