If the land is for sale through an estate agent, ask them if they have a mortgage broker who might be able to help you. I actually got a loan for the last land I bought, through my bank. If you can only get a loan for part of the price then you could probably get the rest on a credit card.
Money is actually quite readily available at the moment. Google "Secured loans". Have you got a business? Get a bounce loan. If all else fails - look at a bridging loan. They used to be prohibitively expensive when bank rate was 5%, but now that it's virtually nothing you can get a bridge for as low as 6%.