I don't know the market for used Boston Whaler boats at this moment, but I can offer some comments on the boat.
A 1989 OUTRAGE 22 is from the production epoch where the liner mold was changed to create a full-width engine splash well. This is a very attractive feature and an improvement over the earlier production models with the small sink-style engine splash well. In terms of other OUTRAGE 22 hulls on the market, it will be one of the newest ones available.
The weather canvas system is a very nice enhancement to the open boat OUTRAGE style, and as you note permits overnighting in the bow area. This is also a very attractive feature.
The FLOAT-ON aluminum trailer from c.2002 is also an important element in the package. Assuming the trailer is completely roadworthy, with good running gear, it adds considerable value to the boat-engine-trailer package.
Regarding the 1999 Yamaha 225-HP engine, I am assuming it is a two-stroke-power-cycle engine. If so, please give more details about the engine. Is it a Saltwater Series engine? Is it an Ox-66 series engine. These older two-stroke-power-cycle engines from Yamaha are from the "golden age" of the two-stroke-outboard engine, that is, they are well designed, well-made, and very good engines. Of course, in 2024 the engine will be 25-years-old and apparently has been used in saltwater--please correct me if my assumption is wrong. The engine age and history of use will limit the value, but on the other hand, if the engine runs beautifully, it can be an attractive part of the deal by not adding the enormous cost of a new engine to the package.
You have an extensive list of accessories on the boat. Whether all of them will be attractive to every buyer is hard to say. But for a buyer who finds them all useful and desirable, they will add significant value.
The final consideration is the comparison of your asking price to the cost of a used Boston Whaler 22-foot OUTRAGE. Here I don't have an exact figure, but I see ten-year-old 220 OUTRAGE boats offered for sale at $75,000 to $90,000. On that basis, I would expect that an asking price for your 34-year-old OUTRAGE 22 would in the range of $30,000 to $37,500.
As always, your desire to sell quickly will affect the price you need to get at sale. If you can wait for the right buyer--someone who wants to buy one of the last classic OUTRAGE 22 hulls made, who appreciates all the add-ons, and understands the bargain of getting a high-quality older two-stroke engine, you should be able to get the higher figure.