A Question About Grading

Right. Coins graded AU-58 in any series are often more attractive than those graded MS60 up to even MS63.

Always buy the coin irregardless of what the holder says. Interestingly enough a lot of classic coins graded by PCGS and NGC in the 1980s as AU58 , will come back today as MS 61 or 62 .
An example , a coin I was half owner with a Vancouver coin dealer a few years back was in a PCGS rattler ( 1894 Morgan) as AU 58. He being a PCGS distributor walked it through at an ANA show and it came out as an MS61 PCGS. Nice profit if you can do that every day.
Grade flation is rampant amongst the top services the last few years.

Here's the problem: If a TPG determines a coin is "uncirculated", then the surface condition and marks become paramount in the grade decision. But if a TPG detects even a trace of circulation (58), these marks become secondary, and even an apparent 64 or 65 falls to the high AU level. The valuation discrepancy between super AUs and medium and especially upper-grade MS coins will always exist, I'm afraid.

I hadn't been looking at graded 58's until recently think I'm gonna start

Bag marks are not wear - they can impact the grade: a heavily marked coin or one with marks that are especially distracting will have a lower grade.

AU58 coins are in beautiful condition with very slight wear on the highest points.

So an AU58 coin often looks a lot better than it's MS60 or MS61 canine cousin.

There are some us who are willing to pay the same price or more for a really choice an smooth AU-58 than an hacked up MS-60, 61 or 62. What you have noticed is something that veteran collectors have learned over the years.

When I was shopping for some early double eagle type coins many years ago (before slabs), I swear some of the coins I saw had been hacked with an ice pick intentionally. The thinking seemed to go like this. "This coin is a AU. How about if I hack up the rubbed surfaces so that you can't see the rub any more and call it Unc. Do you think that will work?"

For some buyers I'd say, "yes!"

It's a complicated subject. If your primary goal is a good-looking coin, then AU-58s are a great way to go.

But AU-58s, even choice ones, will always be AU-58s, and so the upside price potential is probably compromised, much like the case with their beat-up MS60-62 cousins.

If you have an eye to investment (especially in the market-glutted Morgan series), you will need to focus on scarcer dates in higher grades as a rule.

Start slowly and study before you commit - many common TPG 64s can be had for very little money, for good reason.