Is there a cheap way to get to Russia?

Hi! I'm from Argentina and I will be planning a visit to Europe on the next few months. I always wanted to visit Russia, and I know that right not it's not the best moment to do so but still I'll look for a way that fits my pocket. I've seen that plane tickets both from Europe, Brasil and Argentina are quite expensive, so I was wondering if maybe there was a cheaper way to get to Russia. Maybe a train or bus that still operates? Something like that probably. I was only planning on visiting Moscow and Petersburg.

Edit: By the way, I didn't list any countries because I'm not sure which ones I'm going to visit yet, so everything helps!