I assume that, you are reviewing this offer because you get in UK less than what is offered in Qatar.

For me, UK education or UK experience is not a relevant matter here.There are beautiful man made landscape gardens in Dubai, like in palm jumeirah,etc.. What matters is what do you really know. If you are an expert in designing/sketches with genuine ideas, you can convince the employer very easily and get three times of this offer.
If not, you will have to market your CV highlighting on where you graduated from or what your nationality is.Yes, sometime it really works. But, for me not at all seems fair !
Sorry, and good luck