If you use a fisheye lens, there is no need for adjustable heavy expensive heads. All 300$ gets you is feeling special for a few months, until you meet someone with an 800$ head, and for a moment you feel not so special, but then your ego defense mechanism kicks in and you think that someone is silly for having spent 800$ on a pano head and you reaffirm yourself that you made the right choice, but after a few weeks of carrying your heavy professional 300$ head up mountains you realize even 300$ is just as silly for something that does such an incredibly simple job as keeping your lens ~8cm away from the rotational axis
Of course if you want to shoot panos using several lenses, then an adjustable head is nice and the above does not apply. I like the Bushman Gobi head Kolor is advertising, 320 gram! http://bushman-panoramic.com/panoramic-heads/gobi.php
You actually are making my point if you realise you will start with a fisheye but as we all know soon you will try other lenses too. Then you need too drill another hole.
I don't know about feeling special, I feel like that my whole life already so it is not so speciall anymore.