Where on earth are you getting your numbers from?
RAM failure? Modern RAM is such dreadfully unreliable stuff isn't it. Why, I've heard that some people can go weeks without it exploding in a shower of sparks. Me, I've not had a RAM failure in the last 10 years. It's a non mechanical part you expect to last well over 5 years.
SSD? Again non mechanical, but with a known ware rate. If you dont thrash the device 27/7 then it shouldn't be an issue though. It's a socketed component (3rd parties will have the connector cloned long before you need one).
Battery? OK, this is the most likely part to need replacing. The cost of a 3rd party, custom formed 95Whr isn't going to be dramatically less than Apples battery replacement charge, plus they recycle the old one.
If you're worried about any of the above then Apple offer to insure repair costs for you for 3 years. You get the first year covered for free.