Originally Posted by TravelPhotographer

> plea for full words and sentences

Whoops -- sorry!!
Corrected-modified OP.
But questions got answered, thanks!
If I understood "Guv" correctly,
Grabbing (2) BOS-MIA Avios 10K's @ 7P
& then if (2) @ 5P appear, say, 3 days later,
it will only cost 2x$5.60 total to switch...?

Having reached approximate equilibrium
miles+points via cc bonuses ⇌miles+points needed
(~4 int'l bus'n award trips annually, 2 wks ea., just-above-mid-level lodgings)
$150+25 MIP* has greater value than 20K Avios + $11.60...
Am estimating I pay ~20 cents per $1 travel would otherwise cost...^ ^ ^
cc annual fees, IRS 1.87% fees, taxes
(*MIP = Money In Pocket)
Spain flights+14-lodging-nights = miles+points+taxes-fees
Quite chuffed considering me skill level...!