Way too much money. They do go for that high, but it's a bit silly to pay that much for one. I don't personally think you need a lid, unless you just want one. Save the lid for the deep fryer or dutch oven you want. Skillet lids are insanely priced right now.
I just got a second series Erie No. 10 with makers mark for $135 including shipping, and I probably overpaid. You should be able to find a small logo 10 for a good bit less than that. There is one sitting in an antique store right now at my hometown for $55. Has a minor warp in the bottom, but would still work well. With the exception of a grooved handle #10, paying anywhere near that much for a small logo skillet is just getting too hasty. Save your money for a truly nice piece and if you just need a user for now look to keep it at $75-$90 tops, I'd think.
Here is an Erie with 17 hours left on it at $76 + $13 currently.
Here is a Wagner, BIN at $65 + $20, still too much but way better than $300.
Here is a 60s Wagner #10 currently at $9 + $15 with less than two days left on it.
I don't endorse any of these auctions; these are just examples of 5 minutes worth of looking that would be better to keep any eye on than dropping that much money at a dedicated vintage cast iron store, IMO.
Also, where are you located? Finding a #10 with a day's worth of interstate antique store shopping with decent pricing is not THAT hard...