I sold a few Harberts a couple of years ago. Sadly I cant remember what they sold for, the prices are on a spreadsheet on my work computer. I'll have a look when I'm down next week.
Prices in general have risen in the last few years though so I would expect yours to go for more than mine.
As it looks like no one on here is able to give you ball park estimates my only suggestion is to do what I did with my Foreign MOC's and either join a FB group that specialises in Harberts, people in there (assuming there is one) should be able to give you accurate prices. Or list them for sale in one of the auction groups. You'll find people will tag others who they know are interested in Harberts and you should get a pretty accurate price. Plus there are no fees, bar PP which you can specify buyer pays.
Sorry not the most useful reply but hopefully it's something to go on.
They are beautiful though. I'm wishing I hadn't sold mine now.
"You came in that thing? You're braver than I thought!"