Cremation costs will vary depending upon the services requested. Internment of the ashes in a urn only increases the costs. I have seen basic cremation, where you get the ashes in a cardboard box, run between $750 to $1,500. Prices on urns depend on what you buy. I know a co-worker who's brother makes carved wooden boxes for ashes and charges a few hundred dollars to the mortiuary. The mortuary in turn charges several hundred dollars to the consumer. If one choose a more eleborate urn or, one made from polished granit the price can go up pretty steeply.
As much as I hate to say it, IMHO, depending upon where you live $4,000 sounds about right. Most casket funerals I'm aware of seem to be running between $10,000 and $15,000. I'd have to look but, I believe my fathers funeral in 1988 ran around $5,000. It occurs to me that my mothers funeral, which was almost a duplicate of my dad's, was closer to double the cost a short 10 years later. I could be wrong as I haven't revisited the prices of those funeral for a number of year. This is just the way I remember it.