My question has multiple parts. First off, what convinced the Tsar to sell Alaska at all? I know the bountiful resources of Alaska weren’t quite discovered yet, but was the place truly considered useless to them? I know the guy who was behind the purchase on the US side got ridiculed for it but what about the Russian side? The second part is, why did they sell to the US specifically? Surely UK was interested considering Alaska borders Canada. Spain or France probably wouldn’t want it but were they even considered? Lastly, did Russia or SU ever regret losing it? Surely the Soviet Union would have loved to have had a giant base of operations on the continent right?
u/The_Alaskan has written extensively on your first question. While you wait for a new answer you might find his essays in these posts to be of interest.
The short answer is, Alaska was expensive to maintain. And while it was rich, much of that wealth was chewed up by the costs of operations. Russia’s Crimea war with France and Britain showed that Russia wasn’t able to defend its Pacific holdings against the naval powers of the day. The war also left Russia nearly bankrupt. Selling Alaska to the US gave Russia a cash influx and relieved it of an expensive territory they couldn’t defend.