I'm planning to go in 2018, hope I see you there, Mary!
Littlebin, Mary's right--it'll vary greatly based on whether you can drive and stay at home or have to drive/fly and stay at a hotel. The convention itself was around $160 including an optional, additional cost tour. I drove out to this one just because I wanted to see several additional gardens and have the option to bring back peonies (which I did, think I posted a pic of the tiny rental car with peonies bursting out all of the openings!) The rental car and hotel were around $400, then meals. Not super expensive and I can say with certainty that this one was worth it. There were so many tours of gardens, something to do every single day. The last one I went to was Ohio in 2014--there were no tours, just the exhibition (open to public) and dinner, so basically $120 for a meal and to be able to participate in the after dinner auction.
2017 is supposed to be in Raleigh SC. It'll be interesting to see what they have as activities since there won't be any peonies blooming there when the convention happens. I think 2019 is supposed to be in Ann Arbor MI where the UofM historic peony garden is.
I swear there will be more pictures coming, just need to get my garden in order for the summer (still have some dahlias and glad to plant and to check out and turn on drip lines) before I get started sorting them again.
