With that said, i will gladly buy your Otho and some other higher quality RE denarii at reasonable prices
I wouldn't say that the balance has shifted. Most ancients collectors, for reasons that I do not fully grasp, still PASSIONATELY prefer raw coins. I'm not sure how the member status thing works. Is it number of posts or something? But in any case, yes, I prefer slabbing. There are a few of us weirdos lurking around in the forums One of the many reasons that I prefer slabbing is that, yes, I value the expert's opinion. I appreciate ancient coins and enjoy educating myself about the history and so forth, but developing the skills required to distinguish forgeries from fakes is not something that interests me. All that aside, why not list a few coins here in the forums and see how things go? So long as you are not in a rush, I think that it would be a worthwhile experiment. You can do auction style threads and start the bidding at the absolute minimum that you would accept for the coin(s)
You should try the "buy it now" fixed price listing on eBay. I have sold quite a few using BIN and they will automatically relist if they don't sell, with no additional charge.
I recently sold nearly all of my US coin collection. Not quite 3000 coins, but several hundred. I used all of the above methods and more. If I had to do it again I would send the whole collection in one go to an auction house or to reputable dealer on consignment. It sounds like the total value of your collection is enough for some dealers and auction houses to be interested in the whole package. Assuming realistic pricing a dealer should sell the $1000+ coins on consignment easily. The $100-1000 coins should do OK. They may wholesale the < $100 coins. One thing I realized is that average coins, priced at retail values, can sit in dealer inventory for years. It works out for them because they are always turning over some fraction, presumably enough to stay in business. On the other hand, when collectors sell they usually want the money for some reason, they don't want to sit on inventory for years. So there's a cost for selling quickly. However if you really have a 4-year time horizon, you might get slightly more selling them on eBay or Instagram or on this forum. That will come at the cost of hundreds (or thousands) of hours of effort.