Dimension hubs = $20

I wouldn't say that it's a ripoff, but just because a entry level hub is anodized and drilled seriously does not make it worth that much more.

Rim is nothing special, spokes nothing special. Handbuilt? Depends who's handbuilding them and what their reputation is. Handbuilt can mean factory stock, then retensioned (omgz0r) or literally from spoke up.

$280 for that wheelset? I'll pass. You could get a similar wheelset on miche hubs which are much, much better hubs on alex da28's for around the same price.