Make sure you do the math on the cost of upgrades vs just buying the FT kit. Upgrading to V2 shocks alone will cost you $100 when you could order a full FT kit for as low as $200 online, no tax, free shipping (with coupon codes at places like Tower, if you choose not to support your local track/hobby shop). Also factor in tax and/or shipping if you by upgrades later vs kit now. And if you think you'll upgrade the Transmitter, ESC, motor soon you'll find yourself wasting a bit of money.

I suggest doing one of the following:
1. Run RTR stock for a few months to see if you stick with the hobby, then go with a whole new kit if you get really serious. By then you may decide you want to try a different kit/brand anyways. You can then sell your RTR, upgrade it, scrap it for parts, or hand it down to a friend or family member.
2. Start with the FT kit, grab a brushless ESC/motor combo at a small discount (Tekin RS + 13.5T or 17.5T is a great low cost, high-quality option), a good $50'ish servo (there are many great choices - Savox is my current fav for price vs performance), and a good 2.4GHz radio - and hope you really love the hobby. This option is better if you're not short on disposable income. This is also a good opportunity to pick up used components at a big cost savings.