Can a developer change the minimum payment threshold?
No, you can't change the payment threshold. It'll always be either $10 USD (if your currency is supported by Apple), or $150 USD (if it's not).

Source: iTunes Connect > Resources and Help > Getting Paid


  When will I be paid?
  
  Payments are made within 45 days of the last day of the month in which
  book purchases were made. To receive payment, you must have provided
  all required banking and tax information and documentation, as well as
  meeting the minimum payment threshold.
  
  If your bank and bank account currency is listed in this table, you
  must exceed a minimum payment threshold of $10 USD. All other bank
  countries and bank account currencies must exceed a minimum payment
  threshold of $150 USD.