According to Dan :
If you have a vehicle that's suitable for towing, you simply can't beat a trailer for economy and convenience. Renting or delivery is always a possibility, but, having your own trailer means that you'll use it a lot more than you thought you would.
The Impreza might be a bit undersized for this task, so, it's worth checking. If you're going to be limited to city/suburban driving, it should be fine. We originally towed our trailer (that's 500lb empty) with a Nissan Multi which has a 500lb tow limit. With loads of > 2000lb once or twice. Very gently...
For general haulage, a 4x8 trailer like the one pictured here is about the very best choice:
The bed is actually 50"x98", so, getting 4x8 sheets in and out is easy.
Back when we bought ours (over 10 years now I think), a new one with a 2000lb rating was $800, and the 3500lb was $1200 new. Canadian dollars - at the time that was around 550US and 900US.. I haggled the 3500lb one down to $1000CDN.
Note the steel sides and railings. It also has steel rope loops for tiedowns, and the tail lights are just about indestructable (being mounted inside 4" angle iron).
JDJ looks like they've dropped the 2000lb version, and who knows what they charge now. JDJ is Canadian. They have US distributors. The design is pretty simple, so I'm sure that there are US makers of trailers very similar to that.
We have often taken ours on trips of several hundred miles at a go. Handles very well. Mind you, now that's been with a SUV with a 5500lb capacity.
We probably have had this trailer loaded to its limit.
The only mods we've made were to sling a piece of 3/4" sheathing in to protect the floor, and stick a jackstand with wheel to make it easier to move by hand.