A real espresso machine is for pulling café-quality shots at home every single morning for the next ten years, so you want to buy the right one once instead of upgrading twice. Look for brass boilers and heavy portafilters that hold heat well.
Wait for the holiday sales to pull the trigger, and watch for the previous year's model to drop in price. Manufacturers usually roll out updates in the fall, which means older versions get marked down just as deeply as the new ones with zero drop in performance.
The 0% intro window is a hard deadline, not free money, and any remaining balance left when those 15 months end will get hit with regular interest.