Buying 100,000 miles ?

As someone who is new to the buying Y then upgrading with miles technique, do these fully flexible fares change in sales like the lower fare buckets or are they pretty static?

You don't need a fully flexible fare to upgrade, but it is more expensive than the cheapest. It does mean you have to pay extra if you do want to change your flight. I think it was only £50 per person when I changed. My original Economy tickets were about £800 each return to MCO
Dick D

I currently use shops away, Tesco Clubcard and have the Black Virgin Card however adding everything up by the time I have to try book my rewards flights I'm likely not going to have reached the number of miles needed which is 90,000. How often do virgin have a bonus offer on buying miles?