Local pickup and in good condition? $500 is a decent price IMHO. I can tell you in stock form a set of Symphonys are fantastic speakers with a good amp. I was in the market for a new set of speakers some years ago after my speakers of some 30 years died and happened across a set. I knew the speakers from decades ago and own a set of 302s so forgot about the new speakers and grabbed the Symphonys. Never looked back and do not regret it for a moment.
I paid CDN$850 for mine which at the time was about US$600 delivered to the front door by the dealer who was selling them. He had speakers into the 5 figure range and these were knocking out everything I tried them against well into the $5k range. In fact the staff had never bothered to listen to them as they are a bear to over and were amazed when they heard them. After leaving a deposit, I got a call saying the owner had backed out, they were a consignment. I asked for his name and number and was told they'd get it and call back. Wondering, I called the owner and found out the salesperson decided he wanted them and was trying to pull a quick one.
I can not fault him, he was smart but, not smart enough.
If you get them there are some mods if you are of a mind. Pat Tobin has some crossover mods. Also, there is the possibility to change out the internal crossovers and put in the Bozak bi-amp crossover and get the Bozak active crossover. If the set has more than 2 terminals, they are wired for the bi-amp system. If so, make sure you get the active crossover, the N-106 or N106A from the owner. Sometimes it is forgotten.
Good luck and I hope you decide on them.