How much can cost for Old high DA Gambling domain ?

in experience how much will cost per Casino domain ?

let's say DA50+ and 1 year old with 0 spams ?

That depends on buyer and on ideas attached for that domain name development .
In any case your domain name worth as much as real buyer ready to pay for that.

its just not DA, if u using domain brokers cost can go really high, cost depends on lot of things like backlink profile, DA, old topical authority, how easy and brandable domain name sounds..max i have purchased is 2800 usd domain DA 55 but very powerfull and clean domain, 10 years AGE. Second option is you hunt domain urself and it can cut cost down severly