Chris,
I've gone to York for many years and get excited when I find deals and blowout prices.
But when I figure my rental car expense, fuel, food and lodging, just to get there and get around, I could probably stay home and buy my trains on the Internet at full MSRP, and get more trains for less money.
But there is something about the excitement and "the hunt" that makes the York trip one of my most anticipated journeys twice a year.
This past October my adult son came with me and now he wants to come again in April and has joined TCA to do so.
Good luck on finding the cheapest way to get there.