need price info on collector cartridges

Hope the moderator will be generous and cut me some slack. Hoping the good pards that read this may have some helpful suggestions.

Do you have recommendations for websites with info on pricing of collector cartridges? Over a lifetime (I'm now retired and collecting SS) I've accumulated a fair size collection of cartridges, many of them being old and unusual. A bunch originated from a Kraft Cheese box full given to me as a kid by an old gunsmith/collector. My kids haven't shown much interest so I'm going to be selling most of them. Some are too dear and have sentimental value to dispose of.

Now, most are going to be sold at gun shows. Probably the majority will be put in the very small, zip-lock bags and sold for $1 apiece. I'm hoping lots of pards will see items that fill in a niche. I believe, however, that some are worth more. Finding good info on going prices is essential and, again, I'm hoping you good pards have some websites you can direct me to.

What kind of cartridges are represented? A sampling might be interested. Some examples are: black-powder-era 38 S &W, 41 Short Colt, 44 Colt, Spencer Carbine rimfire, old, odd-size rimfires, lots of interesting old head stamps (W.R. A. Co , for instance, instead of Winchester or W-W), 30-06 and 45ACP with WWI dates, a 50 BMG with FA 23 head stamp, some 45 half-moon clips w/WWI head stamps, etc. An old 45-70 is head stamped 45 GOVT. Some 30-40 Krag are head stamped 30 USA, indicating to me that the cartridge was still the current US military issue when they were manufactured.

Anyway, you get the idea. Some good info would avoid pricing reasonably rare items at a dollar as well as putting a ridiculous price on common-as-water items.
Another question -- and I think I know the answer but will ask anyway -- am I correct that these cannot be mailed, i.e., since they are technically live ammo? In truth, this stuff is so old (lead oxide on bullets and heavy tarnish on brass is a dead give away) that it's inconceivable they'd still fire, but I suspect USPS authorities would believe otherwise. Is there a mailing exemption for antique ammo or does the USPS consider that once live ammo is always live ammo?

Many thanks for your consideration.

next door at cast boolits i recall a sticky somewhweres [maybe in swappin and sellin] about mailing ammo.
also the same question over there would most likely recieve many,many more answers.
and possibly a direct link or even a knowledgable collector.
they'll help if they can.