I paid $495 for my Hondata S200b but i've seen S100b on H-T going for $275-300 and S200b for $300-350....
If the DP is 3 inch then $160 is not bad... but I rather make my own too
Hondata tuning for $700 is way too much. I hope that shit is on a dyno. My tuner charged me $225 for almost 3 hrs of dyno tuning and about 30 pulls.... but that's a hook-up.
Socketing a P28 should only run you about $75. That is how much it is locally around here.