Too big?
IMO, to a large extent, frame size is cosmetic ...
- 40 years ago, you would probably have been sent out the door of a bike shop with a 54cm bike ...
If there is a problem with YOU riding a bike with a 54cm frame it would be the limited allowable range for adjustments to accommodate your current-or-future riding position(s).
If you are spending $200-or-less, then a bike with a 54cm frame is more-than-fine ...
If you are spending $600-or-more, then you should probably choose a bike with a smaller frame BECAUSE you can certainly get a "new" bike from a shop for that amount ... particularly, if you can locate a PERFORMANCE BIKE SHOP near you.
That leaves at least a $400
no-man's-land as far as pricing for which YOU will need to decide whether the bike is a good-okay-or-great deal ... or, one which you should pass on.
What is your anticipated budget?
BTW. If I were you, then I would probably try to hold out until you found a ready-to-ride bike OR frame-alone which had the appropriately smaller size.