Hey poster - my cousins are the Worthings- lived in Rumford for years.
Anyway - I just bought first pin for myself and have to say that the market through pinside, craigslist etc is efficient. A couple people buy anything reasonable and flip pins the next day, but most are collectors looking to acquire quality pins with great gameplay for the longer term.
If everyone was buying "to make money by selling for more in the future", then the market is cooked.
But unlike beanie babies, modern sports cards, comic books in the 80's-90's or coins years ago, you can have a blast with the machines and even put them on location and make a few dollars.

So we buy the best we can afford and have fun with what we got and when we sell it we get most, if not more of what we put in. We could do worse.