Don't know if a traveler needs to go through a travel agent - they should apply to the nearest US embassy or consulate to where the person lives. However, typically for someone to be issued a tourist visa they do need to prove that they have sufficient funds to cover their expenses. $3400 seems a modest sum - unless they have bought a tour in which they pay for everything in advance.

If someone want to some here to visit independently - they need to be sure they have enough to cover their costs. They should also have trip and health insurance - since the healthcare system in the US is fee for service (NO free care) and MD visits and medications are typically VERY expensive versus what they are in europe.

Probably need to be on the Americas forum..

Well -

people on the US forum won;t know about Russians getting a visa to come to the US. Can certainly ask there as well - but the OP really needs to talk to the people they need to get the visa FROM.

I suspect the OP is thinking about the "invitation" requirement that, for U.S. citizens wishing to visit Russia, is part of getting a standard visa. Such invitations are often procured through travel agents. But I'm pretty sure that the U.S. does not require such an invitation for Russians applying for a visa to enter the U.S. Ties to home, adequate funds, yes. I'm not aware of any set requirement like $3400 though.