I paid for a bottom job once and it was $1400 for 2 gal of ACT. I was already hauled out and in storage so that was not included. Only reason I paid is because this yard would not allow owners to paint. Current yard allows it and it ends up costing about $250 for the same 2 gallons and about 4 hours (I do employ a professional keel and rudder painter, but it doesn't cost anything!) of time (tape, prep, one gallon for coat 1, wait , a little less than 1 gal for coat 2). The leftover gets used for the jack stand area when the boat gets lifted and I do extra coats at the waterline and on the leading edges. So, 2-2.5 gallons would probably be just fine, depending upon the paint.
In our area, two coats is more than enough to get through one season. Anam Cara was in for two seasons and the winter last year and when we hauled this year a quick power wash was all that was needed, so the ACT worked as advertised.