I am not sure just how abnormal your sizing is... I know mine is outside of the typical US proportions. I have a long torso and short legs, standing 6 feet but a 30" inseam. I am also slightly muscular, but more wiry than bulked up, so it is often difficult to find jackets and pants that fit. Finding a one piece was very difficult, though I wound up being lucky with a Dainese which is aimed more towards EURO than US.
A brand that you may wish to consider before resigning your efforts to find an off rack fit is RS Taichi. They can get closer to the top of your budget, but they have a lot of variation in their sizing. Not only do they cater to US and EURO, but Asian builds as well, so the lines they make are very diverse.
If you are open to a two piece - nearly all tracks will accept them provided they zip together - you will have a much wider range from which to choose. I have Dainese jackets that zip together with other Dainese jackets I own and because Ducati Corse jackets are made by Dainese, they will zip with my Delta Pro C2 pants, which is what the Ducati pants are.
My trouble at the moment is that I have the BMW Sport 2 jacket and I am not sure who makes it. I was hoping that I could figure out the OEM and then find some of their pants. I am thinking it is RS Taichi... they did come with a loose zip belt that can be stitched into other makes of pants which is what Taichi does. So you can find a nice $600 jacket and zip them in with some $500 pants and have a great fitting suit while coming in way under budget for the cost of someone adding the zipper.
Good luck.