the others gave good advice.
i was faced with the same decision last season. dad has an OLD "Bear Bruin" bow in the shed he said i could use. probably older than your brothers..but it had a rest setup for fingers..cant think of the name but its pretty much just a bent out paper clip

, a couple brass pins for a sight, a steel bar for a stabilizer, etc etc...and it needed new strings and cables, plus arrows, heads, etc etc etc...i figured by the time i was done i could have a new bow..that would shoot better than the old bow and i would like more than the old bow.
i went ahead and bought a mid price range bow. i love it. shoots great, pretty up to date, got middle of the road accessories on it for now...it works.
the old bows WILL work and shoot...just to me, being serious about hunting and archery, i just felt my money was better spent towards a new rig that would last me and i would be happy with. i knew there wouldnt be anything about archery i wouldnt like.
if your unsure about if youd like bowhunting, using the old bow would be a great route..not too much invested, so you dont loose. if you find out you like it and want to upgrade, then you only spent 100-150$ or whatever...