Napa injectors are about $50 and look to be rebuilt factory injectors. I went with Napa for mine and did the same for a friends 4runner.

Injectors from Toyota are about 3 times that price.

Another option is to send it (or all of them) in to be cleaned and tested, but then you have more down time.
http://www.rceng.com/
http://www.witchhunter.com/

I sent mine to RCeng one time, but that was 90 or 180k ago. Probably 180.

'97 4Runner, '06 F350, '86 4Runner, '05 WR450
http://home.4x4wire.com/erik