Forget getting chips. The BE200 is long long long out of production. To the chip Foundries miner chips are boutique items and are produced in very limited numbers so zero chance of finding unused chips. Only hope is to find dead miners and harvest the chips from them.
I can't see any link to order from the Bitmain website everything is out of stock.
So it seems,but what other chip works with the BTCGarden unit. I have just been intouch with Bitfury, minimum order $500k around 72k ASICs (bit much considering would need a few hundred in any case to test out etc. before such an investment) looking at alternatives. Have just asked NXP, Renesas & Toshiba about ASICs, but then the design needs altering or start from scratch. (eagle parts foot prints etc. more work)