Purchasing Penumbra Collection for $5

[tanooki]

Hello all,

I just installed and tried out Penumbra. I loved the game and was really looking forward to purchasing the collection. I went to buy it today and the coupon doesn't work. Is there an issue or did the coupon expire? I really hope it's not the second because I like the game and wanted more but can't really justify another $20 purchase right now (just spent $25 on the humble bundle). If anyone can confirm that the coupon is expired it would be nice. I don't see it on the site anymore so I assume it has. :\