Many DJs treat their website (and general marketing) like some couples treat the music. They'll try to organize it on their own or they'll find a friend who will make this at a good price. Those DJs might get the best controller but they'll leave their marketing budget to zero.
For the occasion of the redesign of my graphic design site, I offer website design with a starting price of just 550 euros (out of 750) for those who'll book till the end of March.
The site will probably be worth the cost from the first event you'll book because of it. I have proposed a DJ at a foreign couple that didn't have anything else apart a tacky Facebook page and I'm sure that this was the reason why they rejected him in the end.
From a simple five-page site to a site that will be design-content & SEO king, it will in any case be made by someone who apart from a graphic designer is also a DJ who knows the market. It is easy to confuse you with terms like SEO, robots.txt, tags, 301 redirects. Everything will just work fine.
Do you have texts and photos ready? The site can be on air within a week. The total price depends on the number of pages and how much I will deal with in total.