For plane travel, you'll need an ultra-compact, a small-folding, lightweight stroller (so not the mid-size Joie Litetrax 4 stroller (I mean, it can be done, but it's not the most comfortable option to carry).
I was first thinking about the Chicco Goody. The height capacity is higher, the seat-to-canopy space is tall enough even for the baby to grow, and the stroller'ss seatback is the most upright I've seen on an ultra-compact (it is because it's operated with a lever). Totally fits your budget.
Another buggy I'll mention would be the Maclaren Atom - a small and nice-to-push sturdy little stroller fitting overhead compartments in a plane. And since it's not new anymore, the price is much nicer than it used to be in the beginning.
The last I'll mention is the Quinny LDN. The design is rather special, but it allows a comfy enough push and a tall backrest to last for the child.
I hope I helped! Don't forget to keep in mind that these small compact strollers are great for traveling, but they are smaller in size = less all-terrain, less roomy, and with small wheels. There will be compromises on the stroller because of that. Read more about negatives of ultra-compact strollers in this article, just to get in the picture, but also remember it's the most practical solution for traveling if chosen right.