adjective
cheap, favourable
A1
Günstig means 'cheap' or 'favourable/advantageous' and describes price, conditions or deals. It's gradable: comparative günstiger, superlative am günstigsten. Not a verb, so no auxiliary or preposition. Antonyms include teuer and ungünstig. Common in advertising and everyday speech; also used to mean 'convenient' in some contexts.
Examples
Ich habe ein günstiges Angebot gefunden.
I found a cheap deal.
Das Angebot war günstig, sodass viele Kunden es kauften.
The offer was favorable, so many customers bought it.
Die Bedingungen sind für uns günstig.
The conditions are favourable for us.
Details
Mnemonics
a sale tag with a favourable price
sounds like 'goon-stig' — think 'good price'
Notes
Can mean cheap (price) or favourable (conditions).