Spark is even smaller... for travelling, it's ideal. (If you have a standard sized suitcase, the Mavic will assume like half the space of it... Spark is MUCH smaller). And it's more affordable.
The Spark is significantly inferior to the Mavic, and since the arms don't fold up, isn't even any smaller than the Mavic. I have a Mavic Pro and there's zero chance I'd trade it for a Spark even if price was more of a concern.
Also: no 4K video (makes a significant difference in sharpness even when downsampled), 2-axis gimbal (that's the real killer) and significantly shorter flying time (16min vs. 26min, but that's really more like 10min considering you have to bring it home with enough lead time).
Spark trade-offs are reduced range, doesn't do 4K video, 2-axis gimbal, etc.
I'm not sure what suitcase you have, but a Mavic doesn't even take up half of a hand-luggage-sized bag. I have a 40L backpack I use as carry-on when flying. In that bag, I can fit the Mavic (inc extra batteries, cards, controller, iPad, etc), sleeping bag, air mattress, stove and cooking gear, clothes and food for days of hiking.
Spark is even smaller... for travelling, it's ideal. (If you have a standard sized suitcase, the Mavic will assume like half the space of it... Spark is MUCH smaller). And it's more affordable.