Thats not going to be very competitive though and that kits is discontinued from what I can tell. Plus for an additional $50-$60 bucks You can get a HoBoa Hyper 7 or Hyper SS which are more competitive options. Just my .02
$300ish will get you the HoBoa kit but to get it ready to be worthy of competitive racing youd have to put at least another $500ish in it. That about as cheap as you can hope to go and stand a chance of being competitive. Other wise if you just wanna get your feet wet just start with anything...
I agree with the others. The cheapest kit that I can think of that might possibly be made competitive is this HoBoa Hyper VS but you still have to put an engine, servo, and radio in it. Theyre gonna need to be good quality so you can expect to spend at least $350 on an engine, $100 on a servo...