Build or buy a gas forge | The Forge Fire | Forum

Hello everybody. First post here, so sorry if this has been talked about already. I am brand new to blacksmithing and looking for some advise on a forge. Due to my shop environment i am going to be using a gas forge. My question is this, Build or buy. I have a budget of around $500. I was looking at the http://devil-forge.com/blacksm.....ge-dfprof/  single or double burner. Also open to building one. I have read a lot about the savings in building your own. My only problem is a lack of any real cutting and welding ability. I would like to have the ability to forge weld at some point. mainly looking to work with small materials making knives. Any recommendations are welcome. Thank you for your help.