I recently picked up a beat up 1989 Trek 1200 road bike to take to college with me. I've fixed it up and now I'm trying to go about getting a rear rack installed (I've got a milk crate lying around, so I'll probably end up just using that on top for now). The basket/crate will be used mostly to just tote books and a few groceries and such. I will admit, I am a pretty novice rider and have had to google maintenence and order parts up to now as the local bike shop near campus is closed for a couple of weeks, so there's really nobody around here that I know to ask.

My bike does not have braze-ons and after searching through several pages of threads, basically I've discovered that I should probably get a Tubus adapter kit. I see that the adapters should "work with most Tubus racks" but I don't have the money for a $100-200 Tubus rack. Will the adapter work for a cheaper rack from another brand? Am I missing a different viable option here? I know there's thread after thread on the topic of racks for bikes with no braze-ons, but it's been hard to wade through thus far.

Thank you for any replies to help this beginner learn more about biking.