Buy OpenTTD
According to COST.games OpenTTD can be purchased from 2 different shops: Steam, GOG.
At the moment the most attractive price is at Steam ($0.00).
The lowest price ever for OpenTTD is $0.00.
OpenTTD review
53 users of Metacritic gave OpenTTD an average score of 8.8.
On Steam, 96% of the 11,602 players gave a positive rating.