gambling in different casinos website will make you spend more than your budget, so it's advisable for someone to change a gambling website if it doesn't find the one he or she is gambling with proper, because I know quite well that gambling website especially casinos gambling website sometimes some of them will not give you what you want, so instead of you making use of different sites it's better and more preferable that you use one particular casinos website to gamble and when you not comfortable with such you can switch to another instead of establishing different gambling site, I think it will course a gambler more expense
Spend more or less is not depending on how many sites you play, it is more about how you manage your funds for gambling. You can even spend more in single casino only if you cant manage your money wisely. Simple example, your gambling funds is limited to $1000 per month and you like to play in 4 different casinos. Simply divide your $1000 into 5, so you spend $250 in each casino. Sticking into 1 casino can be boring for some players, that's why there is something called by "alternative". I'm sure most gamblers has at least 1 favorite place to play and has at least 1 alternative place. These gamblers spend most of their money in the favorite place and use the other one as alternative when they get bored with the favorite one.