Best way to sell a record collection

Sold my vinyl gear and am in the process of selling my albums now. I use eBay, ordered cardboard record mailers and ship USPS Media Mail. Sold about 350 so far in less than a year and a half and have about 150 to go. I get good prices and the process is easy.

it's pretty painful to list them and mail them one by one at the post office. When I realize I won't listen to an album again, I take it to my local record shop. (Usually 10 at a time.) He would pay me half of what he would then sell it for. 

So selling one at a time and dealing with shipping is hassle free and worth it? What do you guys find the best method for handling the shipping cost and packing material costs? Is it to include it in the price of the record or as a separate charge?

USPS media mail is very inexpensive...it's a choice between ease of sale and getting more money...I sold maybe 20 individually and the rest in larger groups...

Most value and least painful are two competing goals.  

Pick out the most expensive or in demand records, purchase a 20 pack of record mailers, and try to sell them on eBay or discogs to get a feel for how much fun or a pain the process is. If you have no history and thus no seller feedback/rating, it might be difficult at first.  Keep in mind after listing fees and paypal fees you're going to take about a 16-20% hit on the final transaction proceeds.  

If you're actively a CD buyer, your best value might be to get trade in (store credit) from your local record store. If they don't have your desired CD in stock, I'm sure they'd be happy to special order for you. Best to bring in a couple dozen at a time, rather than your whole collection, since you're likely to get a better deal that way.