Das sind fake news:
ZitatA number of contemporary news reports, including The Times and Daily Record, claimed that the slogan had cost £125,000. But it appears that the slogan itself was not the primary cause of the £125,000, but the physical advertising campaign in which it was used.
In response to a question on the cost of the slogan in the Scottish Parliament, the tourism minister Linda Fabiani said: “No money was used to develop the ‘Welcome to Scotland’ message”.
https://theferret.scot/welcome-to-scotland-viral-fact-check/