Typical cost in a San Diego area boatyard is $25-30 per foot and would include haul out, power wash and 1 coat of paint, doubled up on waterline and leading edges of keel and rudder. A second coat of paint will add 250-350 to that. They will NOT remove all the paint for that price. Extra prep work.... paint removal, blister repair, epoxy primer etc will be mo' money. So.... if you could get a quote for 700-800 got your 27 footer... go for it.
However........ putting bottom paint on a boat is probably the easiest boat project ever if there's minimal prep... You shouldn't have to completely remove the existing paint, unless you're putting hard shell over ablative... and the standard procedure is to power wash the bottom (or have your diver give it a good scrubbing right before haul out) lightly sand and then roll on the paint.
If you're on a budget... you will save a lot of money if you can do your own work. Most boatyards will allow DIY as long as you don't violate environmental and safety regs or hire outside help that aren't on their contractor list.
Power sanding is especially regulated in a yard, and you will be required to protect the surrounding boats from your residue. For that reason a lot of boat owners choose paint strippers over power sanders.
Call around to a few yards to get some quotes. Ask them about DIY conditions. Get a professional opinion on what extra prep may be needed.