Madden 17 groups all of its attributes into five different tiers. Each of these groups sees the cost of the attribute increase the same amount at the same thresholds. Here is an example:
The top tier includes Speed, Strength, Agility, and Acceleration (the four main physical attributes). The cost of these attributes doesn't increase until you get to 75. So it will cost the same to upgrade from 40 to 41 that it does to upgrade from 70 to 71. But once you get to 75, the price jumps 5%. It jumps another 5% to get from 76 to 77. Then it shoots up 27% in cost from 77 to 78. Each of the attributes in this tier continue to climb at the exact same pace. Even if attributes have different base costs, they still have the same percentage increases as they go up.
The Most Expensive Base Costs
That being said, there are two attributes that don't fit into any of the same patterns as any other attributes: Pass Blocking and Run Blocking. They are in a tier unto themselves.
The base cost for the blocking attributes is more expensive than any attribute except speed (see the chart, above on mobile or to the right on desktop). Here's the thing though: Remember how I said Speed starts increasing in cost once you hit 75 (I certainly hope you remember. That was only two paragraphs ago.)? Well Pass Blocking and Run Blocking start increasing in cost once you hit 51.
This is an earlier jump than any other tier. Since the cost of blocking was already so close to Speed and since the cost of blocking increases almost 25 points sooner than Speed, it means that blocking eventually becomes the most expensive attribute to develop.
If you draft a lineman with 70 Speed, 70 Strength, and 70 Run Blocking, it will cost you more to make him a better blocker than it will to make him faster or stronger (or jump higher or kick harder or throw faster or whatever). You can actually upgrade your Left Tackle's route running from 10 to 80 for cheaper than it costs to upgrade his Pass Blocking from 70 to 80.
For some reason, Impact Blocking isn't included in this same absurd tier as Pass or Run. You upgrade Impact Blocking for the same cost as other learned attributes like tackling, block shedding, kick returning, or spin moves. This is probably where Pass and Run Blocking should be.
Once you get into the 80s, Speed eventually becomes more expensive again. Pass and Run Blocking are still costly, but at least they aren't the most expensive attributes in the game. When you are looking to draft offensive linemen, stay away from the ones with C grades in blocking. Even if you upgrade your league's sliders for o-linemen, the cost to develop blocking is simply too high to justify.