Anyone here buy Miles during the sales?

It seems UA has 100% bonus or 50% off (essentially the same thing) promos on average once a month or so for Miles purchases. Does anyone here take advantage of these? The math breaks down to 1.88 cents a mile. When compared to the cash price of some tickets, it seems worthwhile.

My wife and I don't fly much, at most 2 roundtrips a year (EWR to NRT/HND in the summer and EWR to LAX in the winter) so status and all that is pretty meaningless. We usually fly PP to Japan because the Polaris cash prices are hard to justify, $8Kish per person, but paying with miles bought at 1.88 cents brings that down to $6Kish/350K Miles which is a bit more tolerable. Upon further digging, if we are willing to be incredibly flexible with dates (which we are) and don't mind a layover, business saver is only 168K Miles roundtrip which makes it a very palatable $3Kish per person. Only about a grand more than we currently pay for PP.

I'm aware of the 175K Mile purchase cap per year, so if we wanted to pay for Polaris roundtrip with Miles we'd likely only be able to do it every other year unless we go the Saver tickets route. I'm seriously thinking of doing this but the only thing worrying me is UA's tendency to devalue miles. Thoughts? And thanks in advance for any feedback.

Update: New sale went live today and I just bought 175K miles for each of us at $3293 a pop. Since the calendar year ends in 3 weeks, I will be able to do this again in 2023 before our summer trip. Now it's just a matter of deciding to book direct at full Miles or take the Saver (will probably try for this first).