Anno 1701

The best price for Anno 1701 is $3.39 at GOG. 2 shops have an offer that activates in your country.

Some are. This page only shows offers that activate in your country; offers for other regions, or with no stated region, are left out. To see the offers for another country, change your country at the top of the page.

Yes, with a small risk. Publishers create keys to sell in other shops, which is why a key can cost less than in the official store, and once you activate it the game is yours to keep, just like a store purchase. On average 1–2% of keys fail, so check the shop's buyer protection before you buy: the official store does not refund keys bought elsewhere.

Yes. Anno 1701 has multiplayer and a single-player mode.

Yes. Anno 1701 is the full base game. You need nothing else to play it.