I had the same quandry recently. Because my old roller furling gear was shot (a 1986 Cruising Design II - which would not let the jib down because this system didn't have a halyard holding the top fitting up, and the top fitting was locked up because it hadn't been lubricated in 14 years), I bought a new ProFurl LC32 for a great price at a boat show last year. After considering the options of having various combinations of do-it-yourself and professional help, I decided to have the yard at my marina do the work. Since it was time for a haul out and bottom job, I felt that I could get a good price if I had a lot of work done at one time.
It worked out that way. I had gone so far as to price the parts and material separately. Chuck Hughes, who also responded to your post, shared with me his experiences last year. We rebedded our chainplates last year ourselves. Then I got an estimate from my yard. (I also asked a separate rigger for an estimate, but he was too busy to give me one, so I felt if he was too busy to give me an estimate, he might be too busy to do the work.)
The costs came back this way:
New backstay - I'm having a higher split put in, as suggested by Dave Davis, and have already purchased the adjustable split backstay fitting and vang from Garhauer ($50 + $99) - from the yard: backstay material $454, labor $150
New forestay - $196 material (the labor is part of the $600 to build and install the new ProFurl, so figure another $150
All new shrouds - material $1,049, labor $300
Check and lubricate the sheaves - install new main halyard - $112 (could be more if they need to be replaced)
I have a keel stepped mast, and the yard recommended that it be pulled to make all the other work easier (I'm also having a Davis Mega Light installed to replace my old anchor light). Add $200 for the crane for that.
These are estimates, the work is underway, and could be less. But this should put you in the ballpark.
You can also cross check the material costs on the website with the Catalina parts section (old prices, though), and also do a material cost by using a West Marine catalog. My experience was they're pretty similar.
I guess you could do it yourself, as Tom suggests, but it depends on how valuable your time is, your abilities, your time availability, and whether you feel the labor cost is prohibitive.
As far as trust & worry about a good job is concerned, it's more than caveat emptor - get references, talk to people at the yard, and plan to spend some time there while the work is going on. The May issue of Mainsheet had a good feature article about commissioning a new boat, I think it was a C470. Good advice in there.
I had orginally balked at having the mast pulled, but now I'm glad I did. It gave me a chance to clean and wax the entire mast, and rebed the fittings, like the flag halyards which had stainless screws in the aluminum spreaders. I backed them out with a bit of liquid wrench, cleaned up the spalling, sanded it to smooth metal, painted the spreaders, and used Lanocote to rebed the screws. I also cleaned the spalling around the other fittings which are, unfortunately, all riveted on, and painted the mast around them.
The old anchor light would have gone south very soon. Anyone with those old lights should rethink them, because they are fitted flat on the top of the masthead, and there is only a small gasket that dies quickly in the sun.
I also found that I had a conduit inside the mast, but some yokel had wired the anchor light OUTSIDE the conduit even though there was plenty of room. We'll stuff the anchor light wiring inside the conduit, and have no more mast slapping - gee, quiet for a change at anchor!
We're also having a new main halyard installed, and will use the old one as a backup jib halyard, use the original jib halyard (unused all these years with the old roller furling) for the new furler.
By the time this is done, I'll have a lot more confidence in the rig. Some of my swages at deck level were banana shaped already.
When we had the boat surveyed before we purchased Aquavite in mid-1998, the surveyor suggested that we install tangs at the backstays at deck level. If you check yours out you may find that the backstay doesn't quite line up with the chainplates at the transom. The tangs will take that extra out-of-line stress out at those points.
The materials are pretty standard stuff. You have choices on swages, vs Staylock or Norsemen fittings, but swages work just fine. That is really a whole 'nother subject. The boat's well rigged from the factory, and if you copy what you have, you can't go wrong, other than a split adjustable backstay if you don't have one already.
While my experience is different, yes it can be done in the water. It would be interesting for us to hear what you learned from Tom about doing it yourself. Please keep us posted.
Hope this helps you and others who are thinking of rigging replacement.
Best regards, Stu