It's possible to build a machine that can do what you want - but you have to accept that it is a compromise. My own router has a cutting area about 1500x750 and I use it to cut anything from plastic and wood to steel. Yes, it does cut steel but with light cuts and not very fast. That probably cost the equivalent of around €3000. It's not a Haas - or even as powerful as the Chinese vertical mill I have in the workshop - but CNC means that it can do things that the manual mill cannot.

I repeat the advice in the previous reply - take a look through the build logs, think very hard about your real requirements, and start to get some ideas. Then ask questions!