I picked up a Kelty Grand Mesa 2 on sale for about $75 from Dick's a few years ago. Aluminum poles, decent ventilation, and freestanding, so it pitches fast in bad weather. Newer versions have more mesh in the canopy, and they're only about $130. Weighs around 4lbs, and packs well on my SV. I slept through more than a few storms in it, and always woke up bone dry.
When I want even less space to myself, I have an MSR Zoid that packs up tiny. You can even pitch it with just the fly and ground cloth if you're tight on space.
Here it is with my Kelty Weekender sleeping pad.
Rain fly and vestibule.