I feel bad for not reading this sooner, or failing to post earlier. My apologies.
TLDR disclamer: It doesn't hurt to have options. I'd recommend pre-65 90% silver coins in addition to any physical PM's you own.
My quest to buy PM's started with divisible silver. Actually, it started with divisible gold, but I was quick to buy silver shortly after gold.
What really opened my eyes to the value of buying my PM in easily carried small amounts was reading "Patriots" by Rawles.

Sorry for the spoiler if you haven't read it, but in this fiction, a bit of normalcy returns to the area the protagonists reside in. Their neighbors hold a market/dance event. Buying, selling, and trade are taking place at the event during the day. Just like you'd see at a flea market etc. Thing was, everyone has signs that say, "$0.25 in pre-65 US Coin" or something to that effect, for their product. They didn't demand the high prices that we are so used to seeing now. They knew what they were asking for was going to be in silver.
Once I read this, I actually started buying coin rolls from the bank, by the case. Yes, I literally resorted to coin roll hunting. (What can I say, I had some free time one day out of each week.) I felt like an idiot because I knew that a few times throughout my life I had held some of these pre-65 silver coins and hadn't given much thought to it.
Anyway, here I was, years later, looking through six $250 boxes of dimes in a day, looking for old silver. Yes, that's right, crazy huh? Sometimes I'd hunt half dollars. Sometimes dimes. Not so much quarters or nickels. Most of it has been sorted out over the years. There really isn't much to be had. I got skunked a lot on the halves, and the places you go to get rid of the coinage you sort through kind of get tired of seeing you come in with $2000 in coins, so you spread it out among a few different banks, just so you'd stop getting the damn looks. Most banks don't want to sell or order the cases for you if you aren't a customer so now you have all these new bank accounts at places you would NEVER bank at before. Honestly I am amazed at how many different banks serve my city of 30k people. It is kind of ridiculous.
Anyway, I stopped coin roll hunting when the weather got nice again, and have been too busy to bother with it this summer. Snow is coming again soon so I'm sure I'll order a few cases of halves from my banks and give it a shot. Can't beat finding silver at face value guys, believe me.
I got busy, and frustrated with my lack of progress. I had found $8.15 in face value pre-65 coins. I had looked through around $11,000.00 worth of coins. I know because I used to keep very accurate count of my progress. Yes, that number is fairly common odds. You have about 1 in a thousand coins chance to find one that is pre-65.
This kinda got off track, but back to divisible PM's. It is where I first started making my PM investments. I went on apmex and ordered a $100 bag of dimes. Some times I would buy their $1.00 of face value coins on days that spot would dip. What I was really doing was saving up to buy $100 in quarters next. Which I did about 3 months after I bought the dimes.
I felt that having $200 in
change is a pretty damn good start. I mean, the average person has a change tub or something at home. Mine usually carries anywhere from $100 to $300 at any given time. At 300 it is full and I cash most, but not all of it in.
After my pocket change in silver was squared away, I started buying ounces. Its all the same to me though. 22 ounces of silver in 90% silver coins or in .999 rounds is still 22 ounces of silver. You just have to know what you're dealing with.
I feel that having exact change will help in a situation that we might be heading towards. I also don't intend on carrying more than I need to if I am going 'shopping'. I'll have done my recon or prior purchase, and know what I need to take to get what I want. That way I'm less likely to have to die

defending the change that some robbers saw me get from the lady selling @ the bazaar, shop, store, market, etc.
Anyway, hope this gives some insight.