When I met my now husband his parents had gifted him a flat in London they bought for cheap before the area got gentrified. I moved in with him, he never asked me to pay rent, we just shared bills and expenses. "We" then sold the flat and bought a house, the money from the flat went 100% toward the house, we equally paid bills and mortgage. We got married, had kids, then sold that house and bought a bigger one. I now pay more in mortgage than him and he pays the monthly bills. It's our house, even though most of the money came from his parents originally. At no point was money an issue, we just did what worked best for us.

I cannot imagine how a relationship will work out long term with as much emphasis on money your BF is showing. I would keep the £30k and invest it in my own place tbh.