You probably know this Joey, you've been around a while, but I'll post in case it helps others.
If you intend to get both, then definitely get the low BE guy first. But BE only tells you when to buy, not who to buy. BE doesn't tell you how much money someone will make. To figure that out, you need to make a judgement on how much you think they'll average, times it by the magic number (I've been using 14000, but it's probably a little high atm) then you take a little bit off because getting to max value takes forever. You can use the price predictor on footystatistics.com, But I prefer to use Milchy's (still in the first post of this thread I think) so that I can extrapolate past three weeks and play around with different scenarios.
So basically BE doesn't mean buy Averillo by itself. It you think Averillo will continue to score 40 and hold his spot, you buy him because in 8 weeks he will have made 200-250k.
If you think he will score about 28, which is typical of a rookie centre, he only makes 100k, probably not worth a trade, and that's if he keeps his position.
This is very helpful, thanks. Couldn't work out which spreadsheet you were referring to, but MTBs site has been fine for me so far.