I see used horizontal bandsaws on Craigslist all the time for under $400. IIRC, you can even find them on amazon or ebay for about $250 to $300 brand new. Simply rotate the bandsaw to its vertical position, and make a table, and you're good to go.
There was a recent thread where somebody even made a table that set inside the clamp for easy install and removal, while keeping the horizontal cutoff capabilities.
The other option is a portaband and maybe a SWAG table, or a homemade table. I believe you could do a Dewalt or Milwaukee portaband with a SWAG stand for about $400.
Now, it's possible that you could also find an actual metal cutting bandsaw on the used market for $400, but those are very few and far between around here.