$2000 - $3000 + Tuning for Flex Fuel?

Senna-F1

Just had my bone stock Z tuned for 93 Octane and gained what was expected via ECUTEK. For $650 I'm happy. I've seen others make about the same gains, again, by going to E85, another 12 WHP or so. So I figured, I've already got ECUTEK, for $299 I can get an ECA-2 sensor and analyzer, add in some fuel hose, wire to ECU, and just get another tune. It can't be too expensive can it? Got 2 quotes from the same shop. An expensive way, and a more expensive way. With tax and tune (already have license) the highest was over $3500. $2300 for the other method. Both quotes assumed the stock injectors would be maxed out, so it includes new injectors (ID1000) and Pump, lines, fittings, etc.

I'm not questioning the quotes or rates here, just curious if this is what it takes to run Flex Fuel? I haven't seen others mention any of this when they converted to E85 or Flex. I'm thinking someone needs to finally sell a kit that can be self-installed so we can just get it tuned. The tune was only $250, but that's just 1/10 the price of the conversion.