According to the search results, the cheapest knife in CS:GO in 2023 varies depending on the source. Here are some of the cheapest knives mentioned:

• Navaja Knife | Case Hardened (Battle-Scarred)
• Shadow Daggers
• Gut Knife
• Falchion Knife
• Paracord Knife | Urban Masked

Its important to note that prices can fluctuate depending on the market and the condition of the knife. Additionally, the cheapest knife may not necessarily be the best option for players looking for a knife skin.