@VocaliaI think the reason Buyback is in DOTA is to teach you to NOT buyback. Because most characters need that money to stay effective, and buy equipment. It can be okay to do during the end of the game where you being there faster could change EVERYTHING, but during the beginning if you buyback you basically threw most of your resources away.
As a full-on support player (Mainly Witch Doctor/Dazzle) Money isn't as important to me, but I still don't like buying back because I can buy things to support the team instead; mainly keep wards everywhere, but during the beginning of the game I use a lot of my money on mana restoring, so I can keep my pal in check. If I bought back into the game I'd not have that ability. My mana would run out, and I couldn't heal or stun anyone, and be worthlessss.
Of course, Sal is a much bigger DOTA player than me; I barely have 60 hours and he has like, over a thousand, I think. So maybe his opinion would be more detailed
Retreating is all fun and games until Sans shoots up a wall of blue bones through your escape route, damaging and slowing you.