Based on the historical price increases, purchasing an AP voucher ahead of time can be a good investment of your 'tied' up money. We have 4 AP vouchers we bought back in 2012 for our retirement years (we're there now) and plan to activate 2 of them in late 2019 for our AP Year. AP originally $447, now $776 Platinum [DVC prices]. ~74% increase, or 12.3%/yr return on our 'tied' up money. As always, your mileage may vary.