Has anyone tried theLiberator Ramp Wedge Combo? Is it worth the money? I am concerned I wouldnt be able to use it as I am near 300lbs. Is there a weight limit on it?
You’re talking about this one, right? I don’t personally own that one, but I have the Liberator Sex Position Wedge, and the foam is quite firm. I don’t see a weight limit on the product page, but it does state the following, so it may work out for you 
Cushions feature a ‘responsive core’ for reliable support of 2 bodies in any position
Liberator have every base covered, from ensuring their cushions provide ample, reliable support of 2 bodies in motion, to making sure use and clean up is hassle-free.
There is no weight limit but the foam does compress.
I have the single wedge and, at 170lbs I compress the foam at least half way. You may find that, at 300lbs, it would compress far enough to be ineffective.