We've just been chatting about the JST, one of my crew did a transat on the Nelson. He managed to get signed on as a Bosun's Mate, so free sailing and instruction, he just had to pay for his flight. He's only a 20 yr old Day Skipper, but also had his STCW 95's, being a MN Cadet so already steeped in nautical matters.
You have much more experience I think? Got to be worth asking.
Apart from that, yes it's pricey for the miles/days for sure. However there is a high level of round the clock, hands-on instruction. Outstanding staff and very high morale on board I am being told.
( The JST is sadly feeling the pinch, apparently there is talk of selling the Nellie. )
Edit, she will no longer be sailing with the JST. Future to be decided
I did a 9-day trip with www.tallships.org last year which wasn't a great itinerary, but which was discounted to £449. I.e. came out to £50 per day. I think they're usually about £100 per day.
www.tallships.org don't actually have any tall ships right now, mind.
I did one voyage and they were short of crew for the next leg, got on for £10 a day. If they are short there are often last minute deals, and yes, they were interested in offering deals, or watch leader or BM, for people with experience, even me. (I have got a YM, but didn’t have then). You are expected to spend time and effort helping those less able/knowledgable.