There is an easy way to do this, and it's similar to the method from Davehx's guide for the 5 Star Seller achievement in Forza Horizon 3.
Buy a 1983 GMC Vandura G-1500 for 20,050 creditsYou then need to apply a specific design to the van -
search for a design by clicking and type in "Creeper" in the Description box. This should bring up a couple of Mincraft Creeper designs that are well-suited to the van (at time of writing)...I went for the one by chadstrophywife...then
apply this to the van.
Then, auction this vehicle (you'll have to
make sure it's not your active car by getting in another one after you buy it, as it won't let you auction it otherwise).
You can auction a vehicle by either going to the auction page itself and selecting Start Auction, or from the "My Garage" section, selecting the van from amougst your vehicles and choosing to auction it from the options.
Now
set the starting bid at 2K, and the buyout at 23,000K, with a time limit of 3 hours. Because of the love for Minecraft, this will be snapped up quickly. And you only need to sell one, not five like in Horizon 3!
You can monitor your auctions on the "My Auctions" page - when it's sold, it will have that status. Then, press
for auction options, and select "Collect Credits". Achievement will then pop!
What's more, you'll also have made a small profit! Bob definitely is your uncle!