I don't recall ever seeing packs above $25.99 - which merely reflects my (lack of) spending habits. I regularly see $99.99 and $129.99 'values'. [I'm not in U.S., so my packs are priced a titch higher.]

It has been my (unproven) impression that a pack half the price contains pretty close to half the amount of goodies, and vice versa.

However, it contains the same amount of gold pieces. So half price half the stuff, twice the gold. At least for me.

It seems to take about 3 months to get down to the $6.49 ($4.99) and up to the 3M 'Gold of the Elite!', level, the point at which things seem to top out. Prices go down, but so does the amount of gold. Seems each Monday (?) the amount of gold ticks up a notch.

If I follow that, seems you can get the same amount of stuff, twice as often, as a lower priced pack. Half the gold, though.

I have not fathomed when the pack prices drop a level. They appear to return to the same level you last bought at, soon. They also go up a level, and stay there, for reasons I haven't figure out - either.

Cycle seems to be at least 2 weeks, corresponding around the KvK, KvKr cycle. With other things moving in and around that. e.g. Some every three or every other day, others different. e.g. Inquisitor packs.

Few packs have been one offs. Black Friday comes to mind, and a spring time one. I think the Black Friday offer lasted a weekend, the Boxing Day a week. As opposed to pack grouping changes. e.g. The Flourish packs appeared in the spring - I expect a different grouping will appear in the fall or winter.

Test, I think, has a guide in 'Fan Guides', I think, that talks about how the 'Profit' % is an pseudo-number made up based off the arbitrary gold piece prices at the bottom of the offers.

Not infrequently I'll see the same pack at twice the price. The 'Happy' packs come to mind. Examine carefully - they contain different amounts of goodies. Often losing the particular goodies that attracted you to the more expensive pack.