hi there! this site is a great resource. just a couple words of advice before you buy your first game:
1. don't buy from a retailer. use this site (or craigslist) to find a collector who is selling his game privately. you would think you would get more "professional" service from a retailer, and the idea of some kind of warranty or having a real business behind the sale might seem reassuring, but i think almost everyone here will agree you get a higher-quality game for a better price by getting your game from a private collector who has taken care of their machines. retailers tend to get a game in, give it a superficial cleaning, and spend a little time making sure there are no glaring problems. you end up with a machine that's dirty and unreliable. collectors tend to clean them pretty thoroughly, and usually have the game in their collection long enough that they've worked out most every kink and quirk. also collectors don't necessarily have to make a profit on their sale. not saying you can't get ripped off by a collector -- you can -- but it's almost guaranteed you're not getting a great deal from a retailer.
2. all pinball machines require maintenance periodically. don't get frustrated if you buy a machine and there is something wrong right away. often, a switch will go out of alignment during transport, or a cable might shake loose. and things just break sometimes for no reason. we can usually help with that stuff!
3. go play the pin in person before you buy it. don't try to have your first pin shipped to you.
4. when looking at a pin to buy, the first and easiest thing to look for is to open up the back box and check for battery acid damage. most pins have three double-A batteries located on one of the boards. these are there so the game can remember its settings and high scores even when the game is off. but if they go unchanged for years, then they can leak and damage the game. for your first pin, i would highly recommend avoiding any game with board damage.
5. next, make sure you understand how the game you're looking at is supposed to work, at least in general. make sure it isn't wildly malfunctioning. check for a credit dot ( https://pinside.com/pinball/forum/topic/credit-dots ) , and if there is one, check the service menus to see what the problem is. usually it's something minor like a switch not working. this isn't necessarily a deal breaker, but you should know up front what the issues are.
6. obviously, condition of the playfield is very important. check for wear spots. if the art is worn down to wood anywhere, that's bad.
7. have fun and start finding room and funds for games two, three, and four!