VERY wise advice from all here!
I too have had to "mothball" my suits since the era of the casual days, but I try not to look too "casual" by sticking to at least, "Dockers", nice shoes, shirt and a jacket.
But in your case, if your budget precludes you from spending a king's ransom on business wear, the MOST important thing you can do for yourself is to be "groomed".
That is, shirts starched and pressed, suits cleaned and pressed regularly, and shoes kept polished and free of dirt (like your Benz
).
Most of my suit-wearing days hailed from when I was in my 20's, and my modest income did not allow me to sport a 2-weeks supply of Florsheims, Hugo Boss, and silk ties...but I made do with budget, off-the-rack items, but kept them meticulous (harder to do since the materials were not like the better-quality brands). Still, I was often mistaken for one of the executive-level associates (even by them!) simply because I looked the part...having a frame that accommodated "euro-cut" styles didn't hurt much either
).
Even today, I keep my casual wear just as meticulous, and those in my office that are not affiliated with my project STILL believe I am a high-roller in the company!
You are what you project...