Applying for a job has a lot of parallels to applying for bank financing, on both sides of the table. Would you hire someone who came to an interview looking like they didn't take even a little time to prepare, like the job just wasn't important to them?
There is the opinion that the banker is in a sense subservient to you and you owe him or her nothing in terms of mutual respect. That's an extreme characterization of that opinion of course but consider that you are not necessarily looking for a one time loan but you are seeking life long business relationships and networks. Such relationships are built on shared goals and common expectations. Parties engage in and maintain such relationships because they are win-win, beneficial to both. If you present yourself in a manner that makes it look like you have no respect or consideration for the other party (and yourself for that matter)...well it's not helpful. That banker in the little corner office in your home town branch may be on a career path that parallels your growing real estate business and the relationship may turn out to be a valuable asset far into the future.
On the other hand I think if people know what you do for a living and know that you “work with your hands” as they say, and you appear in a suit and tie and it's not a wedding or a funeral, they're going to think you are overdoing it. Now of course many people are wrong when they make assumptions about your job and what it takes to do it well and the person that you are but that's just something we have to live with. As the Davy Crockett character said in the movie, people expect things.
As has been said, usually someone who does not ever wear a suit looks really “wrong” when they do. A suit must fit properly and not look excessively “cheap” of course and the tie must be of proper quality and style...all of that...but just as importantly a man must wear his suit as if he's comfortable in it, not looking like he's out of his element. It's subtle, it's hard to explain but it's obvious when you see it. You gotta be in your element. You can and must stretch and grow, but you don't want to over reach.
I feel a person should give some thought but not to too much to their appearance. They should be clean, neat, well fitted, not worn out and try to dress as is expected the majority of others will. If you don't know, ask...”How do people dress for these events?” But ask several people...don't trust any one person. Don't ask me how I learned that!