HK mags average around $65 each.
MKE mags average around $37 each.
Are the HK mags worth a 75% cost increase premium?
This can only be answered by you.
What I recommend is:
IF YOU ARE ON A BUDGET
Buy 2 more HK mags so you have 3 total. This is plenty for primary use.
Buy 8 MKE mags for range use and "back up".
IF YOU ARE NOT ON A BUDGET
Buy 10 HK mags.
ETA:
KCI ... I have no personal experience, but I've had marginal to very negative experiences with other similar NON-OEM magazines.
ETS ... Some people swear they're functional, but that has NOT been my experience with a variety of their other model magazines.