With your budget I would try and go for two pins. One pin set up is tough, sometimes a pin is just a bitch and you can't get anything to go on it. Being able to just go, ok your shit today lets try this one right next to you. That one will play like a dream. When you stuck on one it can be frustrating. No matter how great a pin is they tend to multiply so its good to have a little reserve in the pin fund.
Don't be afraid of an older pin as far as maintenance I find a pin is a pin and they all require about the same amount of tuning and tweaking. So long as its in decent shape your probably safe. Overall they are very reliable.