Selfsufficientish.com

Hi
I'm looking to put a raised bed on my back patio, approx 4 x 2 ft.
I have 2 solid brick walls in which to put it against but cant decide wether to build one or buy one. Price is always a factor as well as trying to way up pro's n con's.
Will it be cheaper to build a wooden or brick one, and if its wood will I need to line it.
I've also seen some on ebay, both wood and metal, is there any draw backs to having a metal one instead.
I was hoping to find some recycled plastic ones but havent done so far, but did once see something similar on a carboot.
Any ideas & suggestions will be very welcome.

So do you only need two sides, with the walls forming the other two? I'd go for brick if it were me. They are quite expensive though but easier to meet up to the existing walls.
I don't use liners in my wooden raised beds. Used pallet wood works well. It's easy to get hold of (often given away) and it's quite easy to replace odd slats if they rot.
There are a few recycled plastic raised beds knocking about. We got a freebie from some gardening mag or other. It seems to be lasting pretty well. This isn't it but looks similar.
https://www.kedel.co.uk/raised-beds/rec ... bed-1.html

Thanks Green Aura
I'm kinda leaning towards a wooden one, simply because I can get my hands on loads of pallets, just wasn't sure about a liner, but knowing its not required helps.