Free to play : How much can curation rewards pay out?

My content has been upvoted enough so that I will be getting enough SPT payout to buy a Spellbook. However, should I? To figure out I want to look at how much DEC, SPT, and SPS payout.

SPS is easy. It is prominently displayed as 50.86% return right on the SPS management page.

DEC isn't hard. 8867DEC = 1 SPS .389$/SPS = 38.9 cents
and 250 days left in airdrop so 38.9 * 250 = $9.75 until end of airdrop
since 8867 DEC is roughly $8.87 then : $9.75/$8.87 = 110% Return

But how about staked SPT tokens? A Google search wouldn't tell the curation rewards % probably because it depends on how often and which posts get upvoted. However, from my delegated SPT to monster-curator I can at least get an idea as follows:

My investment account Terganmarket has : 3582 SPT staked

Monster-curator paid out : 2.448 SPT

(side note: blockchain information is open so you can sneak a peek on other people's wallets :)

A little math 2.448 SPT/Day * 365 Days = 893.52 / year
But there is also the SPS airdrop at 4 SPS to 1 airdrop point
Which I'd also get SPS airdrop = (3582SPT/4) / (8867Dec/SPS/Day) * 0.389$/SPS = $9.82
and $9.82/.00657$/SPS = 1494

Total of 1494.9 + 893.5 = 2388 SPT which equals 2388/3582*100 = 67% return

At first glance DEC seems like the investment to make. When I get my SPT payout I'll probably only turn half into DEC though. Here is why:

I hate to put all my eggs in one basket.

If half is in SPT I get the SPT token and regular delegated curator payments plus some SPS
The other half in DEC gives me more SPS airdrop payments and some DEC to buy cards if they are a good deal.
Both of them give me SPS rewards which I can stake for additional SPS
The SPS also give me vouchers which I can hold (or sell) for packs in the future.

After a while when I've got a little warchest and income stream coming it...Then its time to get that Spellbook and start battling for daily rewards there too!

Happy hunting everyone :)

Side Notes: I love the math and economics of this game.
...and I hate begging for delegated resource credits. Had to delay post while waiting for RC to build up.