Awesome! Another land before time fan who is interested in history 
Welcome with us AvestheForumFox! 
I don't have any coin collection that comes close to your really impressive one. I guess the most spectacular piece of my collection is a German 1000 "Reichsmark" bank note of 1910. I don't have anything from so much earlier times. Did you buy all your coins or did you participate in archeological excavations yourself?
Although our shared interest in LBT is what brought us together you will find that many other topics some of which you already mentioned in your introduction are being discussed here as well. Please join our discussions or start threads of your own. I'm sure you will like this place.
I purchase my ancient stuff from the more professional collectors through the brilliant means of the interwebs (ebay, numismatic communities, etc). Since I live in the states and nowhere near Europe, I cant participate in excavations (the only Archeology here in the states revolves around ancient Indian burial sites and those peramids we hear so much about)
You can buy them unclean which is the cheapest way of purchase ($1 to $3 a coin, accordingly to the dealer). To clean them, the most professional way is to soak them in olive oil for several weeks then brush over them with a fine metal brush (be careful not to remove patina or scratch the frail surface) this could take several months of soaking and brushing, and it can prove to be a dirty experience as the crust and oil gets everywhere!
to find a coin in perfect condition can often be a very rare experience, most coins in the unclean lots have little or no attribution (detail) whatsoever, most end up as nothing more than a metal slug. a flat piece of metal with nothing on it.
Most of the coins from the dirty lots are bronze, there's an occasional silver, and since gold never gets crustied or dirty (which is an attribute that makes it very valuable) they're NEVER found in purchased dirty lots. They are instantly plucked from the pile by the person(s) who found them.
You can buy coins that have already been cleaned, though these are the more expensive. (just be careful, there are lots of fakes out there!) Bronze is the cheaper easier coins to get $2 to $20, silver coins can range around $20 to $100 dollars a coin (or more according to its rareness)) gold is the most expensive, ranging from $300 to $10,000 dollars a coin.
there's a huge market for the hobby, and if you can afford it and love to study the history, then by any means I'd encourage you to get into it! But read more about it before you go gun'ho and start buying everything in site... a warning worthy to be taken to heart.
