One of the advantages of going second-hand Ryzen is the upgrade path.
I recently built my friend a super budget Ryzen build with a Ryzen 3 1200 and an RX 480(which was free as hand me down from a mutual friend) as whilst this is all he could afford for now next year when say the Ryzen 5 2600 is £100 he can add this to his build himself without any fuss. For the same price could have made him a system with older better performance parts but that would leave him no easy upgrade path.
I recently built my friend a super budget Ryzen build with a Ryzen 3 1200 and an RX 480(which was free as hand me down from a mutual friend) as whilst this is all he could afford for now next year when say the Ryzen 5 2600 is £100 he can add this to his build himself without any fuss. For the same price could have made him a system with older better performance parts but that would leave him no easy upgrade path.