lol god no
It depends on the piece but you're looking at a bare minimum of 3k but probably closer to a baseline of 4k for anything decent. Takafumi Hori's LWA and KLK sketches went for around 3.1-3.3k.
My piece went for 4k but it was IMO a much better piece (really iconic and the style matches the show very well) than either of those sketches and it was done by an art director. Also I feel Hori's stuff isn't really 'on-model'. That said, I got lucky on mine. I talked to the guy I was bidding against and he flat out stated that the only reason I had won at 4k was that his funds were in between banks or something but he really was going to bid a lot higher. If that piece had been at Anime Expo, I have a feeling it would have gone for a lot more. A crappy sketch of Ryuuko by Sushio went for 4.2k.
Now the Yoshinari sketch I have is probably something else entirely on the price scale. Of course I got that one by pure luck so it was free.
Now I will say this, my piece and the ones at Animazement might have been boosted in bidding prices due to the fact that we saw them painted/made live. That never ever happens at these conventions. Anime Expo did something similar for Sushio but really it's very abnormal to see an animator work in front of an audience.