We had an incident today where someone was selling a double emoji TLD for 25 HNS. It was purchased by someone and relisted immediately for 10K HNS.
A second user came in at just the right/wrong time and clicked on Purchase, not realizing the NEW cost of 10K HNS.
The suggestion to help avoid this type of mistake in the future is to simply work the cost into the 'Purchase' button. For example:
Purchase now for xxxxx HNS