I have to put my 2 cents in for the Duratrax Raze.
Parts are very plentiful, and inexpensive. The buggy can take a beating and keep going. It's easy to tune and repair, and runs about $300 as well.
The most recommended buggies for entry level are the three mentioned here: Ofna Hyper 7, CEN Matrix, Duratrax Raze.
all good entry level vehicles, all about the same price, all durable, and easy to repair.
Good luck on your descision, and always remember to have fun!