Toxrill is another case of commander hype. It's a really powerful card, albeit a bit too slow and expensive. Still the EDH crowd loves it and will try to push it in the format.
The price will be determined by its performance and nothing else. Many predict that it will be removed instantly as soon as it lands on the battlefield, which will make many players ultimately remove it from their decks and thus tank the price.
The future of this card on the market will most likely look the same as for Avabruck Caretaker.