For me, the best value was purchasing a 4-keg kit which came with the 4-way distributor (with individual shut-offs, etc.). The price difference between a 2-keg kit and a 4-keg kit was $70 when I purchased a month or so ago.
Trying to piece it together, the cheapest I could find the distributor for alone was about $50 + shipping. That eats up most of that $70 difference and when you add in more disconnects and hose, it wasn't economical for me to buy smaller and upgrade later.
Since then, I've purchased 5 more kegs, so now I've got 9 kegs, 4 of which can be on tap at once. Gives me room to continue brewing, even if we're not consuming as quickly.