During the few weeks I did the Stalk Market, I believe that I got three large spikes. Two were 500-something, and one was somewhere around 400. I don't remember the small spikes that I had.
If you check your turnip prices religiously, you're bound to run into higher prices sooner or later. I kept a spreadsheet and everything, haha.
I've probably had several of them, but I've only ever noticed one since I don't do turnips, and I've heard of rude people who sell turnips in others' towns, but I did have a 500+ spike once and I let someone come over.
Oh yes, I had Re-Tail selling turnips for 640 bells. That was the highest I have ever gotten, too bad I didn't buy turnips because I restarted on May 7th.
The most recent one I've gotten was somewhere in the 400s I believe. I've had several, but it was before I joined TBT and thus before I got my second town. Otherwise I would be super rich now.
A few weeks ago I had them selling for 621. I asked my friend if I could buy some turnips from her town, so I made a enough for the gold badge. There was another time when they were at 400 something. That's about it...
Just once. It was like 587 or something. I made a ton of money on optional tips. Kinda wish it would happen again, so I could afford to buy a high tier dreamie
I had two turnip spikes (519 bells for the 1st one and 523 for the 2nd one) since I've started to play. These always come along with bell account spikes I must say haha (tips for host anyone?)