In comics, condition is everything. A well read copy of Spiderman #15 might sell for $25 while a pristine copy is in the thousands. Take a few pictures and post them in the forum called Please Grade my books.
I wouldn't be in a rush to have them all graded. The key ones, yes but not all. It's expensive( thousands of dollars) and not every SA book will go up enough to justify the expense, plus your money will be tied up for half a year.
Now that you are retired, why not make selling your books your new hobby. Read up on the market, study ebay and some auction houses and dip your feet in the water.
If you decide you want to sell the whole thing, you can easily do it here. Either by yourself or I'm sure people will be willing to help, for a piece of the action. A couple hundred books is formidable but the effort should be very rewarding. Even ragged copies of key Marvels will bring you some decent money.
Best of luck!