basically during the distribution phase VESTS are compounding at around 3% per week, so if you calculate the cost per Mv (million vests) and see a significant dip, then and only then would waiting make sense.
However, if you have to wait for 1 month for a 10% dip, it would have been better to have just paid 10% more and get 4 weeks of 3% gains (compounded)
If your timeframe of waiting is 3 months, then you need a 42% drop in price just to "breakeven" against this increasing ratio of steem_per_mvest
my advice is to just dollar cost average over a couple weeks, it wont get you the best price, nor the worst price. Alternatively to frontload it and become active poster/curator benefits from the increased rate of return from day 1.
Yeah, waiting doesn't work all that well at a highly inflationary scenario.
Btw cost-averaging on the way down is also a nice supplementary strategy. Perhaps if one starts with a budget and leaves a portion unallocated, he can use the unallocated fund to buy serious or extreme dips. The investor following that route should have a spreadsheet automatically calculating the target prices as these will be changing all the time - and obviously he should be adjusting the market orders frequently...
the following might also be a good strategy to complement frontloading: https://steemit.com/steemit/@jl777/how-to-have-your-cake-and-eat-it-to-or-how-you-can-have-your-sp-increase-even-while-you-are-powering-down
The price should drop much faster than that, inflation is high, selling pressure is very high. We will soon revisit the 25 cts area per steem.