The mortuary talked me into buying a dozen death certificates for my dad when he died in 2018. Other than handing one to a couple of financial institutions who made copies, then handed them back, I haven't had to actually give one up.
When my mom died a year ago, I agreed to buy five certificates. That's a total of more than $350 in legal paperwork I've paid for for no good reason. The same financial institutions made copies of the certificate, and weirdly, the trash company required one in order for me to cancel service when we sell the house.
Well, today is closing on Mom and Dad's house, and at long last someone required hard copies of each of their death certificates -- the escrow company. I wouldn't be surprised if they're ultimately returned to me, too.
My suggestion -- when the time comes after your LO passes, order TWO certificates at most. If for some reason you have to get more, order another one after you've had to give up one. It's a huge waste of money buying these things -- $24 apiece here in California now -- and no one actually needs the notarized official version if they can merely see an official one and make a copy of it.
Here in Wisconsin the first copy costs $20. but each additional is only $3., so it can make sense to buy a few more than you might need so you won't have to cough up another $20. sometime later.
Further, the certificate has a border stating it's a felony to copy it (yes, there's probably more than a few unindicted felons waling around because of this) but in any case there's some fancy tech in them that makes scanned copies illegible.
The USA has been said to contain "50 laboratories of democracy" and so it does: every state does does things differently. And so (for example) a probate procedure that may be suitable for DIY in one state may absolutely require an attorney in another.
The place to watch expenses and avoid overpaying is, of course, at the funeral home. If possible, bring a friend with you when selecting funeral goods and services. You probably want a dignified funeral (and probably want family & friends to feel you've done so, but never, ever forget that every FunHome is a business. And, as with other businesses (e.g., a restaurant) you can expect attempts to upsell.
For, truly, by the time you've arrived at the FunHome you've already done as much as you could or ever will do for the dear departed.
I also ordered more than I needed, but I didn't know who needed what. Those that asked for the death certificates made a copy and handled back the original to me.