Not necessarily GB's fault or fault of their service provider.

If you can get to google.com but not GB (any previously working site), possibly a DNS issue. Use the IP address of GunBroker, go directly to the website. http://www.gunbroker.com becomes http://67.220.119.47/
Current GB IP is "67.220.119.47". Works because you skip DNS, but you have to know the current IP beforehand. (IP addr for "www.gunbroker.com" is different than "gunbroker.com".)

See also GB Admin Comment.

DNS down sure does mess with final minute bidders.