Therein lies one of the big rubs. What you consider an improvement that greatly increases the value of the boat, potential buyers may consider a drawback that they will have to undo.
Any time you modify a boat from its original configuration, no matter how small the modification, there are bound to be some people who will not like it that way -- they would prefer the original setup. So that "thing," whatever it may be, that you consider a HUGE improvement, that you think greatly increases the boat's value, may well actually REDUCE the value in the eyes of the majority of buyers.
This, I think, is one of the big contributing factors to so many of the boats that you see sitting on the market for years and years, and never selling. The owner has over-priced the boat because he believes that he has made it so much better than all of the other, similar, boats out there. While potential buyers just see a bunch of modifications that they don't really want, and certainly aren't going to pay for.
That said, there are some modifications that I think are almost universally appealing. Removing teak decks would be one of those. Replacing or rebuilding engines would be another (though only if the replacements are sized very similarly to the originals). Modernizing counter tops and galley equipment (as long as you don't get too outré).
Good luck.
I much agree with about keeping a boat as original as possible... for many reasons.
There are some up ticks that
might invite the interest of potential buyers.
- New or rebuilt engines are of course an important one
- New tanks of several sorts
- New/rebuilt trany and/or new shafts and props
- Recent haul with new through hulls and fresh bottom coating
- Shined above water portions catch the eye
- New canvas and drapes always nice
- Bright work or paint recently refinished or shined
- Shiny railings catch person's eyes too
- Well outfitted galley attracts the chef
- Clean, sweet smelling, well functioning heads with showers are a must
That said - What you do that could create sales-inviting improvements [many could be VERY expensive - to you] may get your boat sold more quickly with a somewhat of a boost in price compared to if the boat was let fall into general disrepair. However... IMO, you will be lucky to get any meaningful price increase compared to other similar lower priced boats on the market. Shoppers do comparatively price available boats.
So... I again say... "I much agree with about keeping a boat as original as possible... for many reasons." And, one important reason is to not loose money thinking that the next purchaser is going to be willing to pay much at all for your previous expensive improvements. Spend wisely on your boat... it represents a depreciating-value as it ages - pretty much no matter what you do!