The ability to truly answer the question of how much a fishing boat would cost to purchase then take care of, really depends on a lot of things but the overall cost will end up being expensive no matter what. The least expensive fishing boats would be Jon boats, usually powered by a small motor or even just ores. These will run you a price of about 500-600$ generally, sometimes a little more or less. It really is based on the condition of the boat and how old it is, but a mere few hundred dollars is nothing compared to the many thousands you will be shelling out for a commercial grade bass boat.
If you would rather not get a Jon boat, there is no where to go on the price scale but upwards from here, unless of course you are fishing in an inflatable raft. To buy an economy grade, used but in good condition bass boat would run you anywhere from 4,000$ to 15,000$. The 4,000$ figure would be on the lucky end of the scale if you walked away with a deal from a friend. Otherwise you may end up with a boat that doesn’t last too long, or one that needs repair, in other words you will definitely get what you pay for with boats.
Now that we know the bigger costs involved with actually purchasing a fishing boat, that initial cost may pale in comparison to the yearly upkeep costs depending on how much use the vessel sees. If it is used frequently, things have more opportunity to come unhinged, rust, and degrade in general. This means more money out of your pocket, and these little repairs can really rack up. Not all boats are incredibly high maintenance like this, but many are, and as the owner it would be a never ending expense. If you have a love for bass fishing and it gives you joy, then it is a more than necessary expense. However be aware that the costs involved can get pretty steep, so be wise about which model you choose and make sure that the purchasing decision is being weighed carefully.