Heads-up chop question

[RobGarf]

I'm hoping to get some feedback on whether or not the chop I made at Saturday's $560 tournament was a good decision.

After being the shortstack at the final table, I went on a rush and actually was 2nd in chips with 3 players left. 1st paid $13,800, 2nd $7,140, and 3rd $4,400.

I initiated a chop discussion but because I was one of two big stacks, I only wanted to do it by chip percentage. The short stack wisely rejected the offer even after we agreed to sweeten his total. So we played on.

First hand I played a big one with the chip leader - solid lag that regularly shows up at Fwds final tables - called him down with AT on QQKK4 board. This led to a complete meltdown on his part (he played like he had to leave but I saw him hanging out afterward) and soon I was headsup with a T480,000 to T320,000 lead and ante and blinds ready to go to 1000/8,000-16,000 for 30 minutes. Even though there was still a lot of play, I brought up a chop again - I know initiating the discussion isn't the smartest move when negotiating but I would have been pissed to end up walking away with only 7K versus 13K. I felt like I was the stronger player but not by much and this was the one player I didn't have a good read on. Plus, the money meant a lot more to me than prolly anyone else at the final table.

I read that a chip-percentage chop isn't as advantageous for the larger stack when it's down to two players so I agreed to a straight chop of the 21K -$10,500 each- but since I was the chip leader, he would have to take the 1st place 13K slip Foxwoods gives out, thus giving me more of a tax advantage.

A FW regular -nice guy and very good 5-10NL player- was nearby and he said that only amounts over 10K get reported (or was it that the IRS only cares about amounts over 10K?) and my opponent agreed with him and then mentioned he was a CPA when I questioned the accuracy of that number. Since he said he'd be taking the tax hit, he wouldn't do this deal.

We finally settle on him getting $11,500 and the first-place 13K slip and me getting $9,500 and the second-place 7K slip. My thinking was that instead of $10,500 each, which is a straight chop and one I was willing to do, I give him an additional $1000 to avoid paying up to $2000 in taxes. Is this a good deal for me or did I fk up?

I'm inexperienced with chopping so if I made a mistake so be it - just want to make sure I don't get taken advantage of the next time. This btw was the first tourney I played in in a couple years (been playing 2-5NL a few times a week for past six months) but the play was much weaker in this than at the cash games. On that note, I've noticed the ratio of solid players to donks at the 1-2NL and 2-5NL tables has increased significantly...the cat has definitely been let out of the bag.)