I really should get around to playing the first two some time.
Don't bother, they're shit. I've only played something like 300 hours between them. Not worth the money.
Hardly worth it then for a measly 300 hours. Seriously, I remember when games used to have longevity, unlike today's offerings that only cater to the ADD crowd. Bloody lazy devs.
To be serious for a moment, depending on how you play them you can complete them in about 20 hours I think, if you go through them and do side quests and talk to your crew and stuff the first one is about a 48 hour game, the second one with DLCs I've been playing for nearly 60 hours this play through, but with male and female sheps, renegade and paragon and different character types and diverging stories you can play through multiple times. I've done 2 play throughs of each to rack that up.