And it is 5-10x as expensive as Glacier itself...
Also, assuming Arc stores your data in a 'standard' way, I only have to worry about Amazon going out of service. Here there is also the risk of this small german company.
Concerning the price, it is indeed a multiple of pure Glacier. However, they include, apart from lots of convenience, also all auxiliary costs that you'd have to manage yourself for a "pure" Glacier account. As noted in another comment, you'd have to keep an eye on retrieval cost, early deletion and additional S3 storage for metadata.
If you're not interested in tinkering with IAM keys and retrieval rates, I still think Bit Chest is a good value proposition.
Disclaimer: I am the owner of Bit Chest.
I prefer to use the space I have on Amazon S3, under my own account with them, which I pay directly to them, than using some other obscure, third party, close beta service.
What is "ct" on your pricing? Just curious.
I understand that most people on HN will probably use Glacier directly, and that is totally OK. The service that I am offering is not "making it possible", rather it's "making it simple, so much so that your grandmother can use it". You do use Dropbox in the same way, don't you? Also, the reason it's obscure is that is less than a week old and has less than 40 users. I wouldn't expect any offering of that age/size to be well-known, so I'm quite satisfied with my obscurity.
ct is cents. For Europe, that will be Euro cents, all other areas will be billed in USD cents.