Have you looked at any of the Chinese machines? Not the cheap end of the range, but some of the bigger machines? A friend bought an Acctek 6090 which he is using daily in his business and which seems to do a reasonable job. It has quite a few rough edges (literally, in some cases) and needed a bit of tweaking to get it running when it first arrived but it's steel and cast iron with profile rails and ballscrews. All up including shipping (he arranged his own), a 3HP water-cooled spindle (about right for this size machine), and USB motion controller, it was around £3K. The difference buys a lot of cutters and material!

I'm not pushing this specific machine or maker but something like this might be an option worth considering.