Traveling mid-April, 2 people on an open jaw RT: IAD>ZRH, then returning CDG>IAD. Outbound purchased in Polaris, return purchased in Premium Plus. Currently holding an MUA into Polaris on the return (cost: 20K miles +$425).

Prices since purchase January 1 have been bouncing around a lot, first up as high as $1750pp more than I paid, today back down within $150pp of my purchase price.

1. If the price for the entire itinerary drops significantly below my purchase price, can I cancel and rebook an intl open jaw? If so, would cancel/rebook be any cleaner than changing and then changing back to the original itinerary?
2. If it is possible to cancel/rebook, or change and then change back, what happens to my MUA? Do I lose the miles and cash?

TIA.