I hate to say it, I really do, but this seems a little pointless to me. I mean having these coins, if they were official and came with a limited 40k starter set would be nice. But made by a 3rd party with poor quality images on the coins. I just can't see any reason to get them myself.
Add into that that he's specifically targeting a GW audience and has used the term "adeptus astartes" I won't be surprised if GW legal send him a nive friendly letter asking him very nicely to stop what he's doing and never do it again.
If nothing else though, it would be neat if coins like these ended up in other kickstarters as some KS only rewards for backing at certain levels (E.G pledge $100 and get this limited edition coin for the faction of your choosing, these will have a certificate with their number on them etc)