I viewed an ex charter boat which was on offer for some 20k less than a one owner model but needed 20k of refurb work.I bought the one owner model.If you have the skills to do the jobs yourself you will definitely save money but you will probably spend the first season working on the boat and not sailing.
I don't think there is anything wrong with buying an ex-charter boat, as long as price is conducive to age and condition.
The biggest thing is to get it out off the water and have a bloody good look underneath. The leading edge of the keel, does she look like she's been clobbered at all. All the other bits you can see, and make a rational decision on.
Sail wardrobe, electrics, and service history of the engine, gas, water, fuel, and rig.
Only speaking from experience, I have bought a few over the years. Been stung before also!
I bought an ex charter 45 footer. Engine has 6,500 hours, but well maintained. Interior was like a new boat due to good care and regular re-varnishing. Price was low enough to put in new engine, re-rig and buy new sails, (none of which have yet been required, though I have had a new backstay and will replace rest of Standing rigging next year) and still be cheaper than a private owner example. Ex charter boats can be a very good buy, but whilst I was looking I did see some very tired looking examples from some other charter companies.
Be careful as some charter companies go for the minimum acceptable specification, smallest engine etc. The result of that is that the engine gets thrashed. My boat has the largest engine option, and was red lined well below maximum revs, so it has remained in very good nick despite high hours.
Another tip is to choose a boat with conventional slab reefing from a company that offers both that and in mast mainsail boats. The reason is that the boats with slab reefing tend to be chartered by the more experienced sailors, and are thus treated better.
Our yot, Rival Spirit, was a well-used charter and it was and still is our first and only craft.
We have spent a small fortune in replacing, updating, renovating and caring for a craft that in purely monetary terms is totally unjustified. As a result we have a craft that is ours, it has been tailored to how we cruise, there isn't a centimetre that hasn't got some of my blood on it (OK very Master and Commander but true). We didn't buy her on economic/rational grounds, we bought her because we loved her. We still do and if you don't feel the same about the ex-charter you are contemplating and are not a surveyor or cold-hearted barsteward then don't buy it.
However, if it calls to you, follow your instincts.
I have sold 2 charter boats. Both were in good condition but engine had more hours and boat had done more miles than a privately owned boat.
In my case I paid the money every year to keep the boat in good condition and any internal woodwork scratches were varnished out each year.
I did speak to one person who was new to charter ownership that informed me that his charter boat was in far better condition than a previously owned private boat as it was regularly maintained but more importantly regularly used!
I have also sold charter boats. I found that a lot of people put the phone down the moment I said it had been chartered. The reality is that you will find lots of dings but it should have a ready-to-go inventory and everything should work.
I would look out for a patched-up stem and cracks around stanchion bases.