Will be getting from my friend his Corbin swaging press that he never used. Should have a couple of dies with it.  Has anyone ever used one?  And it will be for sale in the future along with 5 different diameter for lead wire,  what are they worth?

I have one of Corbins S-Press it has a sticker model CSP-1 one of the sides.
This press can use standard dies and it is what I reload with and you can look up the price on Corbins website.
I bought a stand for mine which makes it easier to use at my bench, I bought mine originally to play with swaging paper patch style bullets for BPCR and it does a fantastic job, it is fun watching pure lead or 1:16 cores extruded through the three openings of one of the dies that is used to set the weight.
I will be interesting to know what your friends dies were intended for as Corbin can make just about anything that comes to mind.

I'm having a hard time sourcing 50 cal bullets over 515 grains here in Germany. I looked at the Corbin years ago and maybe I need to go back and look again

sportslube
For quite some years now, I have been using an RCE (Richard) Corbin press to make .40 & .45 cal bullets for paper patching. Starting with cast bullets (mostly 1:20 tin-lead), I then run them through the swage. My process for this is detailed in my book "Loading and Shooting Paper Patched Bullets". It's a straight forward process and produces highly consistent bullets. The gear is kind of pricey for just my personal use but the whole setup has been worthwhile IMO.

The press is a very robust design and the primary market for them is shooters who make their own jacketed bullets . . . so, swaging a .45 slug up to .50 should not be a too difficult providing you have a .50 die. I've not tried it though. Bullet alloy would play into how much effort it would take to swage them.

The dies are indeed the key to the whole swaging process. Over the years I have gotten away from swaging from cast lead alloy cylinders to casting bullets that nearly conform to the die. Swaging just squishes them a little into final configuration. My cast bullets can be fired as cast or swaged. Either works and for ranges out to 200 yards accuracy between swaged and cast is indistinguishable.