Not to mention realism, I know this is a game, but it's also supposed to be a simulator. Teams overpay for players ALL the time. If someone wants to bid a silly amount on a player then they are perfectly within their right to make that mistake.
The starting price will still be there and people will still having bidding wars, people will still get overpaid. It's about making the game easy and accessible for all players, it's not about saving money.
I just don't see how letting people get a good deal regardless of how much they offered is fair. If they think a player is worth 50k then they should have no problem spending the 50k on him.
I really don't think autobid saves anyone any money. I think the biggest change is it would make this game a little more user friendly and easier to manage. It's a complex game, it's not going to have a huge impact.
In terms of the market, I just don't see it having a game breaking impact, the market will even out a bit. Desirable players sold during lower traffic times will go for more money and desirable players sold during higher traffic times will go for less, because autobidding will increase access to transfer list players to all users. You're correct, there will be a case here and there where someone would've bid an insane amount. My opinion is that it's not a big impact and not a negative impact either. I suspect, with no evidence to back this up, the more common scenario for a user overbidding is when the user feels like "I must have this player" and engages in a bid war. The autobid, in theory, shouldn't change that.
Taking the time to implement this idea is not worth it when you can already decide to bid as much as you want for a player. It's slightly redundant. Especially when there is so many other things (LI dominance and Micro-Nation issues) to worry about.
I don't think it's redundant at all, it's adding automation. I also wouldn't claim to know the proper priority for this among other issues, but making the game easier without disturbing the complexity of the mechanics is a means of retaining users.