tl;dr: the Polkadot fundraiser is done: 485,331 Eth was raised. On the final day the dollar value of 1 Eth was ~ $300.
New contributors will have to wait until the network launches if they wish to purchase dots. The developers have already started to work on the first working Proof of Concept.
Overview
The Web 3 Foundation announced the Polkadot DOT token pre-sale on their main website back in July; however, I can’t find the exact date of the announcement. Shortly afterwards I launched the Polkadot Market subreddit and more recently this website.