too much. probably looking at close to 5 or 6 grand by the time you purchase a cabinet ID and a computer, game, and io boards.
better to try and buy used... this is an old price list, but gives you an idea of what you might have to spend...
https://amusement.itsgames.com/downloads/support/2018/parts_list_2018_golden_tee_golf_unplugged.pdfyou may not buy live unless you are an operator. it's a paid service as well as revenue share. you sign a contract and pay monthly fees on top of a percentage of the revenue the machine makes... this goes to IT.
you might be able to buy unplugged version. i don't believe there are restrictions. i know they charge a premium for the software cause the idea is to make you money back by charging people to play it.
they also have home versions for some of their games. perhaps that might be a cheaper route. just call them up, they'll let you know what your options are. tell them what you got, and what you'd like to convert to. the home versions simply don't have the ability to take money and are straight free play.
in any case you are looking at CID, computer and IO. with game software on top of that.