that's not bad, Pioneer pet are like 2-3 times that, sadlyI buy the Drinkwell filters in bulk from Amazon, and they are a little over $1 each. I don't think that's expensive. I change the filter every other time I fill the reservoir.
We are very happy with the Catit Flower fountain. I have modified it so that the flower is higher in order to have the water drop further (more closely mimics drinking from a faucet).
2 of our 4 cats drink exclusively from the fountain. Since it is so critical, I have purchased a replacement pump (from Amazon which is much cheaper than from the manufacturer) just in case. And, I buy generic filters from Amazon.