Hi, and welcome to LCT. I think the first luxury cruise is the hardest, because the expense seems wildly unjustified. Our first was on the Paul Gauguin, and it was the South Pacific that justified the cost for us--that unattainable dream location. So maybe that should be your choice.
As for deals, the way Regent generally works I think is to put out the lowest fares early (capacity controlled), and then pull these specials as the ship fills up. These can be 2-for-one (unknown on the PG I think), free airfare, percentage discounts, etc. For the Paul Gauguin, the best discounted time of year is right now, February through April. That's because it's "summer" in Tahiti, and a bit warmer and wetter (but still lovely.)
Sometimes there are last minute specials (if a ship is not full). The best idea to get news of these is to register on their website for emails of specials. You also have to poke around to find specials--often, going to the "specials" section does not tell the whole story.
Hope it works out for you.