Need some advice

OTP - lots of bike for not much money.

Thing is, you're going to start messing around with it and changing bits. You may think that you won't, but you will. It'll start with a pair of grips and end in a powder coat. Honestly. Think about that before you start spending.

Building a bike isn't so expensive and there's lots of people who are willing to help. Lots of tools to borrow, too.

Come to polo. It seems a little daunting to start with (I was bricking it the first time) but people are friendly and want to help. We're all bike nerds.

Have fun

Since there's offer for a Bowery for only £225, you'd still be under £400 if you managed to add some powdercoat, nitto bar, deep V, etc.