As others have suggested, one option is to go with a marble effect laminate for now and then replace with the real deal in future. You won't lose out any significant amount, and there are some stunningly good marble effect laminates out there at the moment - as mentioned, the German kitchen suppliers often have good ones and Omega Kitchens (English Rose, Charles Rennie MacKintosh) have some extremely good thin profile (22mm), square edged surfaces in marble finishes.

Another excellent "half way house" is a product called Minerva - more info can be found here. It is a fantastic product akin to Corian, but with the advantage than any competent kitchen fitter can install it himself with normal laminate fitting tools - no expensive templating, offsite machining and professional installing to worry about. They offer moulded in sinks in stainless or white, upstands & splashbacks and the material is repairable. While more expensive than laminates, it comes in well under an equivalent quartz or stone product. They have a really good Carrara finish as well as an incredibly subtle white sparkle finish (think classy delicate shimmer!) and some other grey and brown tones. We're selling a lot more of this than Corian & Silestone now - and for good reason.

Feel free to get in touch with me if you want more info or some indicative pricing.