affordable solution to looking for weights?

hi! since all the gyms closed recently, my boyfriend is trying to start a home gym not only so he can work out now, but also as an investment for the future. however, his biggest problem right now is finding weight plates as those are very expensive. he is a power lifter so he needs a lot of weight, and i am wondering if there is any way to find him plates maybe used or cheaper somewhere rather than buying them new? Or if there is a wholesaler i can visit? we currently have some weights, but no where near how much he needs to squat or deadlift

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this is my first post here so let me know if there is anything i need to fix :D