In that case my advice to you would be not to worry about that right now. In fact I wouldn't spend any money on model trains because your 32yr old self will probably be into something totally different than your present 22yr old self. Save your money and buy a house.
My college years in the late 80's were my most active railfan years. I would take off with a couple of friends and we would be gone for an entire weekend. Thats impossible now for my late 40's self. I have a lot of slides to remember those years though.
Learn some track planning software and have fun planning layouts. Join a club and enjoy the hobby from that end.
Loading up on model trains now would be the last thing I would do......look at this guy...he is having a blast....