When I did my wear ring, I also replaced all the seals around the drive shaft, and on the jet, and all together cost me under $200. Did the work myself, not too difficult, took one day (had to let the sealants dry overnight before I could use it). Actual work was about 2 hours because I pinched the thrust bearing and had to get on here, ask around, and do it twice...I could do it again in less than an hour. This was my first time.
Tell me this...When you hit your gas, full throttle from a stand still, does the XP leave the water, literally? It should jump completely out of the water, you will hear the jet sucking air and the engine revving free for a brief moment before it lands back in the water.
Or does it sorta spin in place slowly taking off? You should be able to be at full speed in less than 5 seconds. If it takes longer, you may need a new ring.
You could also measure the gap between the ring and the impeller, it should be no more than .040". Check those out before you sink the money into it.
If you end up needing to replace it, do a search on here. There is LOTS of really good documentation on how to do it, and where you are likely to hit difficulties.
Mine took about 30 seconds to reach top speed, and would spin forever before it took off. If I made a turn, it would almost come to a complete stop before I could rev it back up and get it moving in the new direction. I could see a VERY large gap, and measured the wear ring after I had it disassembled, it was at .180" or something rediculous like that.
I was very pleasantly surprised when I got it back into the water with a new ring in it.