Tem algum número de quantos bitcoins já gastaram nessa empreitada?

Yeah, that's Slickage's $100k monthly fee. The amounts aren't exact, though. I send approximately the correct amount to an intermediate wallet of my own, and then it gets sent to Slickage via Coinbase.

The total cost will probably be around $1.5 million, which is more than I'd hoped, though not entirely unexpected.

When I first contacted Slickage, I stated my budget as $1.5 million. They estimated that only $1 million would be necessary. But the requirements changed in various ways, and (as always) various unexpected issues cropped up.

The forum money I held has largely been spent now, mostly in the forum software project. Slickage was paid $100,000 per month in all of 2014 and until May in 2015. Since June 2015, they've been paid $50,000 per month. The exchange rate varied substantially throughout this period, but the end result is that most of the BTC was spent.

The rate ($85,417/month average as of the end of 2015) might seem high to people unfamiliar with professional software development, but it's normal. The project is quite a bit over-due and over-budget (the original estimate was 1 year and $1.2 million), but I've been constantly monitoring Slickage, and they've definitely been making solid, continual progress, so it seemed correct to continue to project. The vast majority of total forum revenue was from ads, not donations, but to the extent that donations were used: this software was in fact the main stated goal of donations.

-snip-

Tax is not included for 2017. Because bitcointalk.org is tax-wise a disregarded entity, it's difficult for me to calculate the tax costs attributable to forum activities. I'll do it some other day.