I should think that a new chain, tires, tubes, shifter/brake lines, and if the wheels or BB or headset needs it, repack the bearings. You should be able to get out of the bike store for under 200.
I just helped my buddy rehab his late 80s' MTB this past weekend. We did a new chain, bontrager tires, tubes, handlebars, bar tape and had the shop true the rear wheel. He bought another 50$ worth of tailight, under seat bag, water bottle and crap...spent exactly 200 and the bike is riding great.