From a local stealer? A lot!
Better off doing it yourself, you'd learn what each part does so you can tune it after you reinstall.
Sync is easy and shouldnt be much, maybe 1/4 of an hours wage.
Lots of info with pics in here on how to take them apart. Several people on here that enjoy tearing into them that will help you through as well.
+1. $20 to build your own carb sync tool, and $10 for a can of seafoam spray, and an hour or two of your time. Research the peashooter and shotgun carb cleaning methods on here. Start with the peashooter and a carb sync, and if you've still got some issues, you can go a little deeper with the shotgun. Many have even reported that just by adding a third of a can of the seafoam fuel additive to a full take of gas that they have had great results with clearing up some of the low speed carb circuit issues that tend to develop with these ethanol enriched fuels.
I built the tool pictured below and did my carb sync last week - piece of cake. A few weeks prior I did the peashooter, another piece of cake. My max is running great now, holding a smooth steady idle, and responding top notch.
The tool is 3/8" hose on the board, all linked with a pair of tee connectors - they are all 4' lengths. I then bought a quartet of universal "stepped" connectors from Advance Auto Parts, and added the 5' sections of 3/16" tubing that connects directly to the vacuum ports on each intake runner. The "stepped" connectors doubled as an excellent restrictor for keeping the fulid from moving too quickly.
When I first started my fully warmed up max connected to the sync tool, I was drawing so much vacuum on 1 cylinder in particular that it was raising the fluid in that tube to the point where it was going to suck it out. So, once I identified which cylinder was pulling too hard, I cut the motor before any fluid was pulled out, and backed that carb down a hair. Then I restarted the engine to check again. Better, but still threatening to pull the fluid out of the tool, so I had to cut the motor a second time and back that carb off further still. Third time, it was still high, but sufficiently adjusted to stay on the tool. From their I followed the standard sync procedure.