First you can measure the selvedge edge of the kilt (the bottom) from one end of the under apron to the other end of the front apron and add about half a foot to see how much tartan was really used in your kilt. Should be something over 7 yards, give or take a bit.

Look at the fell---the back of the kilt above the pleats where the pleat edges are sewn together. Topstitching is an inexpensive way of sewing the fell, while true quality machine or handdsewn fells should have essentially invisible stitches holding those sewn and tapered parts of the upper pleats together.

Check out hte lining to see how well sewn down it is and if it completely surrounds you, and for about 6 inches down particularly over the fell. If you can raise the back of the lining up (which you should not be able to) see if there is a lot of overlapping redundant tartan under the fell---if so they did not cut out the excess fabric from the fell--another sign of shortcuts.

Did they take the time to line up the tartan pattern in the tabs that hold the buckles with the tartan of the underlying fell?

Is there a hem on the bottom or a true selvedge (self edge)?

Is there a reverse pleat at the right hand margin of the under apron? Lacking it is a shortcut and way of saving a bit on tartan needed but makes for a different hang to the first right hand pleat otherwise.

Lastly, someone here should be able to tell you how to tell wool from PV, which you should verify.

There are literally hundreds of things to look at in kilt build quality. I am sure others will pipe in with their suggestions.

Congrats on your first kilt. Welcome to the kilted brethren (and sisters too).