Other than what Joe mentioned about the misc. hardware needed, gaskets, gas (im iffy on that one) etc etc, keeping parts in stock is expensive and usually doesn't pay off. Look into the pricing on the lounge and running costs. If you make it so nice that you spend out the ass and have too many things running to where the electrical bill will be through the roof, then it won't be worth the extra "fluff" I actually already have a written plan on a customer area that includes all the ideas listed here plus some that would really put it over the top. Unfortunately you would have to buy these off of me... They aren't free. One small thing I will give you now is that you should provide a GOOD free wi-fi and with that you can transform the area into more than you are thinking... but expansion idea on that is also a money-talks secret.