Sell off BBC Three? Most of its content is stuff that the commercial broadcasters would take and I expect it'd be quite easy to make it profitable without 60 seconds and what-not.
What do you imagine the BBC would actually be selling if they were to 'sell' BBC Three?
The programming is either BBC in-house productions which would be reallocated to other outlets (primarily BBC Two, but potentially also BBC One and Online) or content from third-party production companies which the BBC wouldn't be entitled to sell. Much of the content produced is either part of an existing BBC property (such as EastEnders, Doctor Who Confidential, Strictly: It Takes Two etc), or just isn't distinctive or compelling enough to be worth buying when a potential buyer could come up with equally middle-of-the-road ideas for themselves (Young, Dumb And Living Off Mum; Great Movie Mistakes etc). Existing agreements for third-party content would have some value, but obviously only for the remainder of those agreements, and only if the broadcast rights contracts are transferrable; it doesn't necessarily follow that just because you buy a channel that you automatically inherit all of its broadcast rights - some rights agreements include renegotiation or termination clauses if the licensee is sold or liquidated.
There are no studios to sell off with the channel, and no broadcast or transmission equipment to be sold as this is largely third-party as well.
Any original formats worth anything would be retained for sale/licence to other broadcasters in order to extract maximum value from those properties, rather than being sold outright.
The brand wouldn't be worth anything but it's inextricably linked with the BBC; the third channel in the BBC's portfolio. Anyone buying the channel would obviously have to remove the BBC branding, and 'Three' as a standalone brand has no marketplace equity, in the way that 'Choice' might have had if the BBC prefix were dropped from it. For the same reason, the channel website wouldn't have any real value as it's integrated with the BBC site and the existing channel branding; the cost of replacing this design would outweigh its purchase price.
BBC Three costs tens of millions a year to run, but that doesn't mean it's worth anything like that once you've removed it from the ecosystem that it's currently part of.