First of all take care of the shoulder and wrist. I had 2 right shoulder dislocations and had 2 surgeries and over 2 years of rehalb. They basically cut my arm off and sewed it back on with all the tendons and muscles about 1 inch shorter than natural. I'm left handed, can't do a push up, can't arm wrestle, loosing an arm wrestling match would rip my arm off but I can now anchor a 70 lbs draw bow. Not all 70 lbs draw bows though.
Not all bows are created equal. I just drew back a right handed PSE X Force that I was told was set at 80 lbs- it felt like 60. I have A Parker Hornet set at 70 lbs, it feels like my Hoyt Xtech at 60 lbs. With up to 80 % let off and with some of the new cams out, try a few and you might be surprised at to what you can draw with the right bow for you.
Another option is a contraption I saw on TV awhile back. Not sure the name but it holds your bow at full draw, you aim and pull the trigger, cock it simular to a crossbow. They were showing a little boy handling a 70 lbs draw bow with no problems.
Your bow price I can't help you with. If it's more than 2-3 years old, most likely not worth much as trade in. Wish I could remember the name of that contraption but if my shoulder goes out again, I'll be finding it, looked like a better alturnative to a crossbow, being it will work on your bow that you are used to. Good luck.