The Raiders sent out emails to season ticket holders yesterday, offering early-bird discounts if you "opt-in" (before September 18th) by agreeing to purchase postseason tickets in Oakland, if the games take place. You must give them your credit card number now, but you aren't charged until the Raiders are guaranteed they will play each playoff game in Oakland.
The playoff ticket pricing is reasonable. Actually, if the Raiders play in the wildcard round, the price of that game would be exactly the same as a regular season game (ranging from $25 per seat in the 3rd deck to $150 in the club section). Check out the price chart by seat section. A 3rd deck seat would only run you a total of $113 for the entire playoffs (wildcard game, divisional playoff game, and AFC Championship game). You would only "pay as you go". You aren't charged for a game until it's guaranteed that game will take place in Oakland.
Season ticket holders who opt-in, also receive 500 points on their MYRAIDER NATION account, redeemable for various items.