Bitcoin expensive because of its price value is high. Yeah, it is right, when we play with bitcoin then we take a big risk with our big money but if we win then no doubt we have double bitcoin. But instead of it that bitcoin is going to expensive but still people like to play with it and continuously gamblers are playing bitcoin gambling. Because bitcoin has more online gambling sites other than coins.
It is the same when we play with other altcoin as well but if you think that it is expensive then you could just use a very small amount to play. Most site allow you to gamble as low as 100 satoshi, that is less than $1 so it should be fine. The main thing is that when you want to withdraw from the site, the transaction fees is quite high if you use bitcoin