Buying LG G3 motherboard with bad IMEI

Hello, this is my first thread ever so sorry in advance if I make mistakes or brake rules.

I own a Sony Xperia Z3+, but I also have my old phone, the G3. I doesn't start up anymore and when it does it shows the LG logo but immediately goes to a blue screen and turns off. Internet says the motherboard is dead... So I want to buy a cheap new one on Ebay and have found one (link at the end of thread).

It says it's a motherboard with a BAD IMEI... I've searched what this means. But I only want to use it for games like Clash Royale and stuff. Can you guys help me out if I can buy the motherboard and can use it. Or is it not safe to buy it.

Thanks in advance.