I recently got a used Rancilio Silvia from a guy on Facebook marketplace who said it is 12 years old, used a few times, and then was sitting in the basement for the last 7 years. Visually it looks perfect, with just a little dust.

I got home and filled it with water, primed the boiler, tried to get water to come out but nothing was flowing.When I press the espresso button, the machine rumbles which is good, but water does not flow out of the group head. The steam wand seems to work properly, but maybe it is just using residual water in the pipes.

I tried the diagnostic test to see if you can run hot water out of the steam wand, and that did not work, so I am almost certain that the pump is bad.

I've seen that a replacement pump is about $30 online and people have said that the repair is easy, but I'm wondering if I should instead try to return the machine to the seller on Facebook marketplace, because he promised that it worked perfectly. I'm guessing he just tested it by turning on the machine and pressing the espresso button, hearing the boiler/compressor kick into action, then he figured it's working and turned off the machine without actually pulling a shot of espresso. The guy didn't seem too knowledgeable about espresso because I asked him if it had ever been descaled and he didn't know what that meant.

I bought it for $500 which I considered to be a decent deal, and would love to hang on to it, but not if there is a high risk of further complications after replacing the pump.

I'm tech savvy and somewhat handy with tools, so I would be happy to replace the pump myself if you guys think I should hang on to the machine.

Definitely learned my lesson and next time I'll ask the seller to pull a shot before selling it to me.

Please help this noob, what would you do?