If you or anyone you can bum off of has played through a Legacy game- it's a great place to steal prototype components. Why? Because no one is (likely) going to play it again!
Pro Tip: components
Although I've not used them for anything just yet, I have all my miniatures left over from Risk Legacy while the board and cards were requisitioned to recycling looooooong ago.
Odd. I would think someone shelling out for a legacy edition would keep all the stuff. Like a special edition package for a video game.
I hit my local game store for damaged/misprints/mis-shipments/etc.
I pick up folding game boards for a couple bucks, a copy of Eurorails that shipped with the wrong components for $4 (big puzzle piece board, couple hundred cards, mini plastic poker chip things, wooden pieces, and a box.) I also grab card games from that section. Solid cards for $1-$2 a pack that I can sticker over, and often contain 108+ cards per pack. Game mats for $2-$4.
Definitely something to consider, but having to buy and play through a $50-$80 game just so you can use the components is a little expensive. Obviously you're not playing the game FOR the components, it's just funny how the "tip" was worded.
For me? Either a quick trip to the local hobby store (Michael's, Hobby Lobby, etc) does just well or (in my case) I just happen to have a publisher I can utilize components from. Of course found objects around the house do nicely as well.
I just get all my components from thrift stores. I have so many around me that I can get whatever I need and it's super cheap.