Where abouts are you? I have a new old stock one that I bought in exactly the circumstance that you're trying to avoid. Turned out to be a lambda sensor problem so I put mine back in it's box having wasted a lot of time and trouble locating it (at the time they were out of stock at the local main agents).
There are also much cheaper non genuine ones on ebay, but the landrover forums seem to suggest that they may not be ideally set up. However they may give an indication of whether your problem is MAF related or something else.
If you live nearby I could lend you mine to see whether it helps.
pm me if you don't get sorted.
Malcolm T
