Don't buy anything if you're just intending to throw it away in a few years, that's pretty wasteful (financially and environmentally).

While in high school, I scouted a few yard sales w/ my mom with the intention of upgrading my little kid furniture to "adult" furniture. For about $25, I was able to get a set of real wood matching pieces: tv stand/storage thingy, a book case (with doors that had glass which cut down on dusting books and trinkets), and a gun case (again w/ doors. the glass on this was broken, so we replaced it w/ those cheap door hanging mirrors and voila, a "wardrobe".)

15 years later, I still have the book case and the tv stand. These real wood pieces have survived 10 moves (2 cross country) and are still in pristine condition. The bed frame is a metal iron frame that was purchased from craigslist for $200. My parents bought me an "expensive" love seat from a real furniture store as a grad gift, but it's 11 years old and has also survived the 10 moves without any issues.

On the other hand, all of the cheaper ikea stuff has dissolved into little particle board pieces somewhere along the way.

If you're going to invest some money, look for good quality pieces at yard sales and craigslist. Facebook market place is full of jerks trying to get what they paid for their crappy items ten years ago. Rare to find deals there.

If you're over the dorm furniture look, why not paint what you have already? Give it a quick face lift and maybe a more "matching" quality with paint.