Now, I do not want to spend any more money than I need to on this, preferably none at all if I can manage it, especially since I do not know, as yet, whether or not I will go to any more re-enactments. So my question is, after all this rambling pre-amble, what would be good to wear to show that I am trying to fit in, but not totally authentic, which I cannot afford at present.
As a former reeenactor, I would suggest contacting a local reenacting group and talking to them first before investing money in "the hobby". Most reenacting units/groups will have a "probationary" period for new members to allow them to try things out and see if they like reenacting enough to invest so much time and money.

In addition, some groups will have "loaner" clothes and/or equipment.

From personal experience: research your period before you take the field, and seek out "old veterans" for their counsel and advice, especially when you start buying kit.

Todd