making offer ! Help with reviewing.

I found a SFH, 2bed, 1 bath built 1913, 1253 sq ft.
Motivated seller, moving into bigger house. lived in house for 20 yrs
asking: $25,000
zillow est: 50,800 / epprasial est 40,700 / based on recently sold homes sq ft calc est 66,500

using ARV est of 40k at 70% less 10k for repairs and 5k my fee
going to offer 13,500

then post for sale at 18,500
What do you think? Am I missing something? I the offer to high?

Yea that wud be a good offer to make. However unless your seller is distressed and motivated it’s unlikely he will accept.
If seller calls and he seems motivated and willing to talk about the repairs and his situation I will definitely go talk to him in person with a contract out in the car. If your targeting advertised houses you can expect the sellers are not extremely desperate.
I got a response from a post card this morning and seller wanted 650K for a big old house built in 1930
It sits in downtown in the worst area of the city. I got off the phone quick.