Ditto the buying used.
I got a perfect condition Tornado off of Craigslist about 1.5 years ago for $125.
Thats an incredible deal. Tornado foosball tables (especially the coin-ops) would fetch much more than that especially one that is "perfect".
Also - Tornado tables are made with MDF. You don't have to be a master wood maker to build one, since you'd want a Tornado table - you'd have to buy Tornado parts. The parts will add up to much more than $400.
Bearings, rods, men, goals, playfield, score counter, pins, silicone, playfield strips - and plenty more things will probably set you back around $700. You won't save much money. I used to play a lot of foosball, and we only played on Tornado tables. They are expensive to purchase, and expensive to maintain.
If you decide to get a table for yourself and your serious - you want a tornado table and you want the tournament table - these cost around $1,500.
If you just want a game table in your game room - get the toys they sell at Walmart.