Creating a twitter account takes 5 minutes and making 3k followers will require 15 days of hard work. Infact, you can use Hootsuite or buffer paid apps to grow your content / network. Instead of paying someone in open market to buy their twitter account.

Always remember, if someone has to scam you they will take your money and will not give you twitter accounts in return. Hence, better to do a little bit of hard work but stay safe