Crab fishing season will starts from 6th November.
At some places, you can eat freshly caught crab on the day(6th Nov) although it will be depends on the weather.
Many inns will be offer their dinner with crab after 6th November so if you wonder the reason of high charge of accommodation expenses, that's could be the reason until spring.
In Tango region, this season's crab is called "MATSUBA-GANI(松葉がに)". Especially, in Taiza town, their fishing area is very close to the land(up 30km away) which means less transportation time and much fresh than the other port's crabs. So this crab has a special name "TAIZA-GANI(間人がに)" to given this name, crab must caught in Taiza.
BUT "Taiza crab" became too well-known and it costs a lot to taste (around 50000yen/person), and if you know the right place to eat "Matsuba crab", it is not that different quality compared with Taiza crab. Basically, Matsu crab lunch starts from around 20000yen/person.
Anyway, to eat crab, you need reservation before or stay at accommodation which offers crab dinner.
Without reservation, you have almost no chance to eat really fresh crab! So I highly recommend you to book before.
These two restaurants serves good quality crab!
*Toriki http://seasidekyoto.blogspot.jp/2013/01/toriki-japanese-style-inn-with-high.html
Price starts from 23100yen/person*reservation is only possible from 2people.
(This picture is 23100yen course)
*Torimatsu http://seasidekyoto.blogspot.jp/search?q=torimatsu
Price starts from 18900yen/person.