Go see it. See how it fits.
Unless you really know your anatomy and preferences, and unless you can really read a geometry chart, "frame size" numbers are pretty inaccurate. Too many variables ... even in the way to determine "frame size."
If you are 5'8" and of normal (what?) proportions, a 53-cm frame Could fit you without having to resort to extra-long or short seat posts, stems, setbacks, etc. But until you are sitting on the thing, you won't know.
As for any other part of the post ... who knows?
Is this an "I plan to buy a new bike" thread? Is this a "What good road bikes are available for $150?" thread?
If you want to ride a bike more than around the neighborhood for 15 minutes after dinner, you will want a bike that fits well and is set up to suit you. If your current bike doesn't meet those requirements, you should get one that does.
If you budget is only $150, pretty obviously you are at the mercy of the local used market. However .... you are probably better off struggling with your current bike (look into a seat post with less or no offset, and a shorter stem) than buying a bike which is almost good just because the price is right.
If you have some tough hills to climb you will want low gearing or maybe a triple. Obviously you want a bike that basically fits. You want drop bars ... and if you plan to own the bike for a while, you probably don't want to buy something really old unless you like the whole C&V (Classic and Vintage) scene .... where spending weeks looking for one elusive part is part of the fun.
Check out the Aurora and anything else which shows up in local classifieds and looks okay ... but Always go with the mindset of "I am not going to buy this bike unless it is a miracle." You might find one of those "garage queens," a bike someone bought years ago and rode three times and parked .... or just a good, solid bike which you can make work for you. The biggest and most common mistake (IMO) is to buy a bike because you really want a bike, only to find out later that it is also not really the bike you wanted .... fit isn't quite right,. needs too much repair, isn't really equipped for what you want it for .... all stuff you overlooked because you were eager to buy a bike.
But only you can prevent forest fires ... or estimate how well a particular bike might suit you.
One final warning ... the less you spend up front, as a rule, the more you spend later. New tubes, of course .... well, the tires are rotting, so new tires ... the bar tape is falling off ... the cables are rusty ... oops, so is the chain ... the brake shoes are like rocks .... the headset feels just a Little notchy ... what's that weird squeak from the front hub?
One way or another you pay for what you get, so make sure you are getting what you want. Nothing like spending all your available cash on the wrong thing and regretting it ... based on personal experience.