I've traveled a ton with my little ones and planes and trains, buses, you name it, and finding a that model stroller that doesn't fall apart after a few trips was key for us on a budget like yours... Look for easy one-hand folds that don't require acrobatics, especially when you're holding a squirmy six-month-old. always test by folding and unfolding multiple times to see if anything sticks or jams, because that can be a nightmare on the go.
Durability comes down to solid construction, like reinforced joints that don't creak under pressure, and bigger wheels for those rough sidewalks in neighborhoods like ours. For lasting through toddler years, a recline that goes flat is nice for naps, and adjustable harnesses that fit as they grow. On planes, gate-checking with a bag protects it, and for buses, something slim that fits in tight spaces without blocking aisles. I rinse off grime after trips and oil the hinges lightly, keeps everything smooth. Yeah, it's held up through two kids now, no issues.