First decide whether you want long term quality (OEM Sanden only) or a cheap short term resolution. Then search on eBay as there are legit stores that sell rebuilt compressors and at least one that apparently sells the same Sanden brand compressor as you would get from the dealership but much less expensive.
You can also go safer and order from an online honda parts dealership, like HondaPartsNow.com, which is still cheaper than local dealerships but not as cheap as the aforementioned Sanden on eBay.