The average cost for an oil change is between $25.00 to $40.00 depending on who you take the car or vehicle to for the oil change.
When you have an oil change the oil will be drained out and the oil filter should also be replaced with a new one and then new oil added to the engine.
Some vehicles take less oil than others so that can also factor into the cost of the oil change.
I do my oil changes mostly unless I don't have time to do it and when I have had an oil change place change my engine oil I paid at most $40.00 for the oil change which was worth it.
That's not too expensive but you can change oil and filter yourself pretty easy for around $20.00 and your time or whatever your oil costs and your oil filter.
Always replace the oil filter when you change the oil because the oil filter contains old oil which can mix with your new oil and cause engine damage.
Oil filters are pretty cheap when compared to an engine.