If you are looking specifically for the cheapest entry into the 1/8 Ebuggy scene, there's a few options:

1. Used previous-gen race buggies like a Tekno EB48.3 or Associated RC8B4e
2. Arrma Typhon 3s starts at $330 RTR
3. Kyosho NEO 3.0 VE Readyset RTR $430
4. Serpent XRS8-e RTR $450

If you are looking for an outdoor basher, Arrma has a variety of other vehicles based on the same platforms as well, just with varying bodies/arms/wheels/shocks. Traxxas now has 4x4 brushless 2S models of the Slash, Stampede, Rustler, and Rally starting at $330, and their 3S VXL models at $400. Team Associated Pro4 SC10 and Rival MT10 are also highly-regarded durable bashers.