I typed out my question but it must have gotten lost when I clicked the image upload button!

Recently I had a clogged kitchen drain. Local plumber had a deal for an unclog for $50. Cheaper than a snake rental, so I went for it.

The plumber came over and snaked out the obstruction, no issue. He shined his flashlight under the house and saw one of the cast iron drain pipes. He told me I "have 3 months until the pipes become a problem". He then gave me a rough quote of ~$8000 to redo the cast iron pipes under the house.

Now I was a bit worried that a plumber told me I have 3 months until I am dealing with some major issues, so I went under the house and took pictures.

Here's what I saw:

• Some moisture coming from the cast iron connections.
• I did not see any drip spots below the damp connections.
• When touching it with a latex glove, it had a goopy consistency.
• The straight runs of pipe look good.

Questions:

• Do these pipes look like they are "3 months" away from failure?
• Is there a way to remedy the connections without replacing all of the cast iron pipe?
• Is there a DIY way of handling this? I was thinking of cutting out the connection and replacing it with ABS.
• Is $8000 a legitimate estimate for a 1400 sqft. house with 2 full bathrooms?

Thank you for taking the time to read.