Personally, a coach is nice and a very valuable tool, but I would recommend getting software like Fritz and really studying all the GM games you can find, as well as your own. A strong engine can really point out mistakes you are making over and over, and come with very detailed opening books which can teach you decent lines.
That's sixty dollars total for a GM whenever you need one.

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However, I do agree that if you have the money, why not take a lesson or two, see if it's worth it! On a side note, 2300 is super strong, but if you can find a GM who charges similar rates, I might go that route!