No, there is only 2 series of comic figures released so far. Series 2 is still widely available - many of them on Amazon for $10 or so.
Series 1 is the only one no longer available and last I checked, its prices were nowhere near what TV series 1 is going for. You only have Rick, Michonne, and 2 walkers to catch up on there. And Rick and Michonne had a few variants (SDCC Michonne with hood and blood, NYCC Rick with blood) which makes finding one cheaper a bit easier.
The SDCC Gov rocks BTW. Can't wait for Negan to arrive - this week hopefully.