Much covered in previous posts. I had this dilemma last year when I needed to move a 32 Avant. In the end I decided to get the local B&O dealer to provide the transport. In the event, an initial estimated cost of 'about £100' became an actual cost of £200, and in practice involved two personnel and a small hired van. If you have two man+ capacity to lift the Avant into a van then I would do my own van hire and keep the Avant upright. You can probably get a 'man and a van' for £50: just be sure that the TV is carefully lifted using the handholds and don't get a van with a high threshold.
Having said that, the price/value of all Avants continues to tumble, so it might make more sense to just take a chance. The 28 Avant is probably a bit easier to handle. The B&O instructions for transporting the BV1/ BC1 involve lying the TV on its back, angled to one side following the case contours. I would guess that the right way to carry any CRT is similar, as recommended above. Face down is not recommended (although many have apparently done it successfully!)
Graham
I used to be indecisive, now I'm not so sure. [W C Fields]